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MANUAL OF 

MENTAL AND PHYSICAL 

TESTS 



A BOOK OF DIRECTIONS COMPILED 

WITH SPECIAL REFERENCE TO THE EXPERIMENTAL 

STUDY OF SCHOOL CHILDREN IN THE 

LABORATORY OR CLASSROOM 



GUY MONTROSE WHIPPLE, PH.D. 

Assistant Professor of the Science and Art of Education, Cornell University 

Author of "A Guide to High-School Observation," "Questions 

in General and Educational Psychology, 

"Questions in School Hygiene." 



WARWICK & YORK, 

INC. 

BALTIMORE, U.S.A. 
1910 



Copyright, 1910 

BY 

Warwick & York, Inc. 



'G(,A27ri5:;? 



MANUAL OF MP:N TAL AND PHYSICAL TESTS 



PREFACE 

Hitherto the literature of mental and physical tests has been 
scattered in numerous journals; the results obtained by different 
investigators have too often not been compared; indeed, in many 
cases where the methods have been divergent, comparison has 
been impossible. In consequence, there have been no recognized 
standards of procedure and none of performance. Neverehe- 
less, I believe that the time has now come for the taking of an 
account of stock, and for the systematization of the available 
materials. This conviction, which is the outgrowth of my own 
interest in the experimental study of mental capacities, an interest 
that has been with me during the past ten years, has been con- 
firmed by many suggestions from colleagues and friends, who 
have pointed out that a manual of directions for mental tests 
would meet a real need, and might further the cause of investiga- 
tion. More particularly, at the instigation of Mr. C. H. Stoelting, 
of Chicago, who has undertaken to supply the apparatus and 
materials prescribed in this volume, I began, in March, 1906, to 
prepare a small handbook 'of mental tests. The impossibility of 
adequate treatment of the subject in small compass has, however, 
necessitated the expansion of that early undertaking into the 
present work. 

In the introductory sections of the volume, I have sought t 
show the general purposes of mental tests, to lay down rules 
their conduct, and to explain the methods of treating data, 
this connection I discuss the calculation of measures of g' 
tendency, measures of variability, indexes of correlatio 
other statistical constants. 

In the body of the volume, I have brouglit together, f 
treatment, some fifty of the most promising tests. In 
my plan has been to sketch the development of the 
scribe a standard form of apparatus and method o^ 



explain the treatment of the data secured, and to set forth the 
results and conclusions thus far obtained. 

The tests that I have selected may not prove, ultimately, to 
be those of most value, but they are, I think, numerous enough, 
and varied enough in type, to furnish a working basis for 
investigations for some time to come. 

In the choice of materials and methods, I have sought to fol- 
low a middle course; on the one hand to avoid the use of costly 
instruments of precision and of the elaborate methodology of 
the psychological laboratory, and on the other hand, to avoid the 
inexactness of make-shift apparatus and the unreliability of 
casual, unsystematic observation. My idea has been to supple- 
ment the exposition of the standard apparatus and method of 
procedure by suggestions for variations of apparatus or of method, 
so that each test will be carefully standardized, yet will retain 
a sufficient degree of flexibility. 

Doubtless, to some readers, the instructions for the conduct 
of the tests will seem unnecessarilj^ lengthy and detailed; but 
experience has convinced me that faulty results are to be traced, 
in quite the majority of instances, to the neglect of some seemingly 
trivial detail in the arrangement of the experimental conditions; 
so that instructions can scarcely be made too explicit in a manual 
of directions in which standardization is the object. 

In explaining the treatment of data, my aim has been to make 
clear the arithmetic of the various formulas, without insisting, 
in every case, upon acquaintance with the mathematical reasoning 
upon which the formula is based. 

And when I speak of "the results and conclusions thus far 
')btained," I speak with the intent to make clear what, I am sure, 

made evident more than once in the text, that this book presents, 
a closed chapter in the experimental investigation of mental 
'ity, but a program of work to be done. 

icknowledgments for aid should be numerous and ungrudg- 

ese have been made in part in the text, but in many in- 

laterial assistance has, perforce, gone without explicit 

ment. I wish, however, to make clear my indebted- 

Stoelting Co., for the loan of numerous cuts, to Dr. 



PREFACE IX 

Guy L. Noyes, of the University of Missouri, for assistance in the 
tests of vision, to Dr. H. H. Goddard, of Vineland, N. J., for the 
adaptation of the Binet-Simon tests to American conditions, to 
my colleague, Professor I. M. Bent ley, as well as to my wife and 
to my mother, for the reading of proof, and to my colleagues, 
Professors Charles DeGarmo and E. B. Titchener, for almost daily 
advice and encouragement. 

The inscription of the book to Professor Titchener is in token of 
my special debt to him as a teacher and as an expositor of the 
scientific method of attack in the solution of the problems of 
mental life. 

Guy Montrose Whipple. 
Cornell University, 
June, 1910. 



TABLE OF CONTENTS 



INTRODUCTORY 

Chapter I. 
The Nature and Purpose of Mental Tests 1 

Chapter II. 
General Rules for the Conduct of Tests 4 

Chapter III. 
The Tre.\tment of Measures 9 

THE TESTS 
Chapter I\'. Anthropometric Tests 

Test 1. — Height, Standing and Sitting 51 

Test2.— Weight 56 

Test 3.— Diameter of the Skull 60 

Test 4. Girth of the Skull 66 

Chapter V. Tests of Physical and Motor Capacity 

Test J.— Vital Capacity 70 

Test e.— Strength of Grip 74 

Test 7.— Strength of Back t> 79 

Test ^.—Strength of Legs 82 

Test 9.— Endurance of Grip • 82 

Test iO.— Quickness or Rate of Movement : Tapping 100 

Test 11. — Accuracy or Precision of Movement : Aiming 115 

Test 12. — Accuracy, Precision, or Steadiness of Movement : Tracing 119 

Test 13. — Steadiness of Motor Control : Involuntary Movement 123 

xi 



Xll TABLK OF CONTKNTS 

Chapter VI. Tests of Sensory Capacity. 

Test ;^.— Visual Acuity 131 

Test.15. — Balance and Control of Eye-muscles: Hetcrophoria 142 

Test /&.— Color-blindness 148 

Test 17. — Discrimination of Brightness 159 

Test 75.— Auditory Acuity 166 

Test /9.— Discrimination of Pitch 180 

Test ^0.— Discrimination of Lifted Weights 188 

Test 21. — Discrimination of Pressure 194 

Test ^^.—Sensitivity to Pain 198 

Tcs<;?S.— Discrimination of Dual Ciitancous Impressions 207 

Cmaptek VII. Tests oe Attention and Perception 

^Test ;24.— Range of Visual Attention 222 

Test 25. — Visual Apprehension 244 

Test .35.— Cancellation 254 

Test .27.- Counting Dots 270 

Test ;2S.— Reading Complicated Prose 273 

Test ^5.— Simultaneous Adding 277 

Test SO. — Sinudtaneous Disparate Activities 279 

Chapter VIII. Tests ok Description and Report 

Test Si.— Description of an Object 286 

TestS2.—Y\dii\\{y of Report : Anssane Test 292 

Chapter IX. Tests of Association, Learning, and Memory 

Test 33. — Uncontrolled Association (Continuous Method) 313 

Test 34. — Controlled Association: Part-Wholes, Genus-Species, and 

Opposites 319 

Test 35. — Controlled Association: Computation 327 

Test 36. — Learning: Habit-Formation in Mirror-Drawing 343 

Test 37.— Learning : Substitution 350 

Test 38. — Memory for Serial Impressions: 'Rote' Memory 356 

Test 35.- Memory for Ideas : ' Logical' Memory 394 

Chapter X. Tests o^ Suggestibility 

Test 40. — Suggestion by the Size-Weight Illusion 405 

Test 41. — Suggestion by Progressive Weights 410 

Test 4^.— Suggestion by Progressive Lines 414 

Test 43. — Suggestion of Line-Lengths by Personal Influence . . . . : 419 

7V.S/ 4.^.— Suggestion by Illusion of Warmth 423 



TABI.K OF CONTENTS XI11 

Chaptku XI. Tksts of Imagination and Invention 

Test 45— Ink-Blots 430 

Test Ifi. — Linguistic Invention 435 

Test -(7.— Word-Building 441 

Test 45.— Ebbinghaus' Completion-Method : Mutilated Prose Test 445 

Test 49.- — Interpretation of Fal)les 454 

Chapter XII. Tests of Inteij^ectual Equipment 

Test 50— Size of Vocabulary 45S 

Test 51. — Range of Information 465 

Chapter XIII. Serial Graded Tests for Developmental Diagnosis 

Test 52. — De Sanctis'- Graded Series 469 

Test 53.- Binet-Simon Graded Tests : 1905 Series 473 

Test 54.— Binet-Simon Graded Tests: 1908 Series 493 



List of Materials 518 

Index of Names 521 

Index of Subjects 527 



INDEX OF TABLES 

TABLE PAGE 

1. Strength of Grip, in Hectograms, 50 Boj's (Whipple) 10 

2. Values Derived from the Data of Table 1 ll 

3. Distribution of the Heights of 12-Year-Old Boys 13 

4. The Numerical Smoothing of the Distribution of Table 3 22 

5. Probable Error of ?• for various Values of r and of n (Yule) 32 

G. Conversion of ii-Values into r-Values in Accordance with Form- 
ula 33 36 

7. Correlation of Right and Left-Hand Grip, by Group Averages 

(Whipple) 37 

8. Relation of Deafness and White Color in Cats (Yule) 39 

9. Corresponding Values of r and U for Formula 40 (Whipple) 40 

10. Norms of Stature of American Children (Boas) 53 

1 1 . Norms of Standing and Sitting Height (Smedley ) 53 

12. Norms of Weight (Burk) 58 

13. Norms of Weight, with Clothing (Smedley) 58 

14. Diameters of the Skull and the Cephalic Index (West) 63 

15. Breadth of Head by School Grade (Porter) 64 

16. Skull Dimensions and Proportions of Entering Classes at 

JNIunich (Engelsperger and Ziegler) 65 

17. Circumference of the Head (MacDonald) 67 

IS. Norms of Vital Capacity (Smedley).* 71 

19. Value of the Vital Index, when Weight is Taken as Unity (Kotel- 

mann) * 72 

20. Norms of Strength of Grip (Smedley) 76 

21. Types of Endurance in Dynamometer Trials (Binet and 

Vaschide) 92 

Opposed Types of Endurance (Binet and Vaschide) 92 

Sample Record of a Tapping Test (Wells) 107 

Dependence of Rate of Tapping upon Age (Smedley) 109 

Test Numbers for Auditory Acuity (Andrews) 170 

Pitch Discrimination of 167 Children (Seashore) 184 

Dependence of Discrimination of Lifted Weights on Age 

(Gilbert) 192 

28. Pain Limen for 50 Boys and 50 Girls of each Age (Gilbert) 204 

29. Topography of Esthesiometric Sensitivity (Weber) 212 

30. Average Number of Letters Read Correctly in One Exposure- ' 

(Whipple) 232 

31. Effect of Practise on the Perception of Letters (Whipple) 236 



INDEX TO TABLES XVll 

32. Relation of Visual Range of Attention to Age (GriffingJ 236 

33. Individual Differences in Visual Apprehension (Whipple) 251 

34. Effect of Practise upon Visual Apprehension (Whipple) 251 

35. Effect of Letters and of Fatigue on Cancellation (Whipple) 262 

36. Averages and Variations in Cancellation Tests (Whipple) 263 

37. Correlations in Cancellation Tests (Whipple) 264 

38. Effects of Fatigue on Cancellation (Ritter) 265 

39. Relation of Average Number of Letters Cancelled to Intelli- 

gence (Winteler) 266 

40. Effect of Different Methods of Reaction in the qrst-Test 

(Whipple) 268 

41. Specifications for Test-Cards Used in Dot-Counting 271 

42. Results of Reading Tests (Whipple) 275 

43. Simultaneous Reading and Writing (Sharp) 281 

44. Comparative Accuracy of Sworn and Unsworn Statements 

(Stern and Borst) 305 

45. Effect of Time-Interval on Range and Accuracy of Report 

(Borst) 307 

46. Dependence of Report on its Form (Stern and Borst) 308 

47. Effect of Practise on Coefficients of Report (Borst) 310 

48. Distribution of Terms in 'Uncontrolled' Association (Jastrow, 

Nevers, Calkins) 317 

49. Influences which affect 'Uncontrolled' Series of Words or Draw- 

ings (Flournoy) 318 

50. Normal Performance in the Part-Wholes Test (Norsworthy) 321 

51. Normal Performance in the Genus-Species Test (Norsworthy) 322 

52. Normal Performance in the Opposites Test (Norsworthy) 326 

53. Correlation of Opposite Tests with other Tests (Aikins, Thorn- 

dike and HubbelD- 327 

54. Efficiency in Addition: Five 10-Minute Periods (Schulze) 336 

55. Efficiency in Addition and Multiplication (Burgerstein) 336 

56. Efficiency in Computation within a School Session (Laser) 337 

57. Additions made per Pupil with and without a Rest-Pause 

(Burgerstein-Schulze) 338 

58. Effect of Pauses upon Computation (Friedrich) 339 

59. Effect of Fatigue on Arithmetical Work in Evening Schools 

(Winch) 340 

60. Effect of Practise on Speed in Mirror-Drawing (Whipple) 346 

61. Substitution Test. Number of Symbols Written, Form B, 

Group Method (Whipple) 353 

62. Substitution Test. Speed in Seconds, Form B, Individual 

Method (Whipple) 353 

63. Substitution Test. Bright and Dull Boys. Individual Method 

(Whipple) 354 



1 INDEX OF TABLES 

8ul)stitution Test. Distribution of Gains and Losses in Speed 

(Whipple) 355 

Use of the Footrule Method in Scoring the Memory Test (Spear- 
man) 367 

Norms of Memory Span for Digits as Conditioned by Age 

(Smedley) 374 

Development of Memorj^ for Digits (Smedley) 374 

Memory for Letter Squares in Relation to Age and Practise 

(Winch) 375 

Percentage of Accuracy in Memory for 2-place Numbers 

(Schuyten) 375 

Sex Differences in Memory Span for Digits (Wissler) 376 

Net Efficiency of various Memories, in Relation to Age (Pohl- 

mann) 376 

Dependence of Memory Span for Auditory Digits on Age 

(Jacobs) 377 

Dependence of Memory for Auditory Digits on Age 

(Ebbinghaus) 377 

Memory for 9-Term Series of Different Kinds (Lobsien) 380 

Norms for Memory of Related and of Unrelated Words 

(Norsworthy) 381 

Dependence of Memory upon Form of Presentation (Pohlmann) 382 
Relation of Memory for Auditory Digits and Intelligence 

(Ebbinghaus) 386 

Relation of Memory for Digits and School Standing (Smedley) . 388 

Memory Span for Digits in the Feeble-Minded (Johnson) 389 

Comparative Memory Capacity of Normal and Feeble-Minded 

Children (Norsworthy) 390 

Recall of Different Members of a 7-Term Series (Binet and 

Henri) 390 

Old Homestead Test: Words Written and Underlined (Whipple) 399 

Percentage of Loss in Third Reproduction (Henderson) 400 

Force of Suggestion (Gilbert) 408 

The Progressive-Weight Suggestion (Binet) 413 

Percentage of 'Yields' to Contradictory Suggestion (Binet 

and Henri) 421 

Suggestibility to Warmth: Resistance-Coil IMethod (Okabe and 

Whipple) 427 

Suggestibility to Warmth as Related to Age (Guidi) 428 

Average Number of 'Names' given to Ink-Blots (Kirkpatrick). 433 

Scores of Seven Adults in Developing Sentences (Sharp) 438 

General Results in Word-Building (Whipple) 442 

Sex Differences in Word-Building (Whipple) 445 

Dependence of the Completion Test on Maturity (Ebbinghaus) 451 



INDEX OF TABLES XIX 

94. Average Vocabulary in Relation to Scholastic Status (Kirk- 

patrick) 461 

95. Distribution of Corrected Vocabulary-Index (Whipple) 462 

96. Overestimation of the Vocabulary-Index (Whipple) _ 462 

97. Dependence of Range of Information on Age (Whipple) 466 

98. Dependence of Range of Information on Sex (Whipple) 466 

99. Results for 25 Children in the Binet-Simon Tests (Decroly 

and Degand) 491 

100. Critique of the 1908 Binet-Simon Tests (Decroly and Degand) 515 



LIST OF ABBREVIATIONS 

A. G. P. Archiv fiir die gesammte Psychologic. 

A. J. P. American Journal of Psychology. 

A. P. Annee psychologique. 
Ar. P. Archives de Psychologic. 

B. J. P. British Journal of Psychology. 

C. C. Columbia University Contributions to Philosophy, Psychol- 

ogy, and Education. 
E. P. Die experimentelle Padagogik (after vol. 5, Zeitschrift fiir 

experimentelle Padagogik.) 
International Magazine of School Hygiene. 
University of Iowa Studies in Psychology. 
Journal of Educational Psychology. 
Psychologische Arbeiten. 
Psychological Bulletin. 
Psychological Review. 

Psychological Review Monograph Supplement. 
Philosophische Studien. 
Pedagogical Seminary. 
Schiller-Ziehen, Sammlung von Abhandlungen aus dem 

Gebiet der padagogischen Psychologic und Physiologic. 
Report United States Commissioner of Education. 
Studies from the Yale Psychological Laboratory. 
Zeitschrift fiir angewandte Psychologic. 

Zeitschrift fur Psychologic und Physiologic der Sinnesorgane. 
Zeitschrift fiir padagogische Psychologic. 
Zeitschrift fiir Schulgesundheitspflege. 



I. 


M. S. 


Iowa S. 


J. 


E. P. 


P. 


A. 


P. 


B. 


P. 


R. 


P. 


R. M, 


Ph. S. 


Pd. S. 


s. 


Z. 


u. 


, S. 


Yale S. 


Z. 


A. P. 


z. 


P. 


z. 


P. P. 


z. 


S. 



INTRODUCTORY 

chaptp:r I 

The Nature and Purpose of Mental Tests' 

When we speak of a mental test we have in mind the expei i- 
mental determination of some phase of mental capacity, the 
scientific measurement of some mental trait. 

The mental test in some respects resembles, in some respects 
differs from the typical experiment of the psychological laboratory. 
Like this latter, the test is superior to the casual observation of 
everyday life because it is purposeful and methodical: it thus 
l^ossesses all the merits common to experimental investigation at 
large, viz: the control of conditions (including the elimination of 
disturbing, and the systematic isolation of contributory factors), 
the possibility of repetition, and the possibility of subjecting the 
obtained results to quantitative treatment. 

Unlike the typical experiment of the psychological laboratory, 
the mental test ordinarily places little or no emphasis upon intro- 
spective observation by the subject, in part because of its rela- 
tively short duration, in part because it is frequently applied to 
inexperienced subjects who are incapable of aught but the mcst 
elementary introspection, but more especially because it is con- 
cerned less with the qualitative examination or structural analysis 
of mental processes than with the quantitative -determination of 
mental efficiency; because, in other words, it studies mental per- 
formance rather than mental content. It is also Coihmonly sim- 
pler in form than the psychological experiment. 

' The tests mth which this volume is concerned are mainly mental tests. 
Since, however, the intimacy of the relation between mind and body makes it 
well-nigh imperative to study their interrelations, attention has been paid to 
the more important anthropometric measurements and to those tests of 
physical capacity that have most frequently been used in the search for corre- 
lations of psychical and physical ability. 



2 NATURE AND PURPOSE OF MENTAL TESTS 

The purposes for which mental tests have been developetl are, 
of course, varied, but, roughly speaking, we may distinguish a 
theoretical interest on the part of laboratory psychologists, and 
a practical interest on the part of those who are concerned" with 
mind at work in everyday life. 

Historically, it appears that most of the tests now in use have 
originated in the psychological laboratory, either in the natural 
course of the development of experimental psychology as a system, 
e. //., the usual tests of sensory discrimination, or as a consequence 
of special attempts to study mental capacity, particularly the 
interrelations of various mental capacities and of mental with 
physical capacities. It is, we think, not too much to hope that in 
time the application of mental tests will bear rich fruit in this 
field. We may hope that the skillful study of mental functions 
by the test-method may supply us with a satisfactory account of 
the nature and interrelations of mental functions, just as the 
typical introspective experiment has been able to furnish an account 
of the structural make-up of mind. If we could, to take an in- 
stance, obtain an exact science of mental functions so that we 
could know the unit-characters of mind as the biologist knows, 
or expects to know, the unit-characters of plants and animals, 
the study of mental inheritance would be carried apprecialjl}' 
forward. 

Outside the laboratory an active and ver}' natural interest 
in mental tests has been exhibited by those who are busy with 
practical problems to the solution of which the scientific study of 
mind may be expected to contribute. It is, naturally, the edu- 
cator to whom the development of a significant and reliable 
system of mental tests would most appeal, since he is concerned 
with the development of just those capacities of mind that these 
tests propose to measure. 

There has been, unfortunately it seems to us, a disposition in 
some quarters to speak as if a science of mental tests was already 
achieved; as if, for instance, a child's native ability could now ])e 
measured as easily as his height, as if his suggestibility or his 
capacity for concentration of attention could be determined as 
readih' as his skull circumference or his breathing capacity. To 
make such assertions is surelv misleading, foi', as the study of 



NATURE AND PURPOSE OF MENTAL TESTS 6 

the tests herein embodied will show, there is, at the present time, 
scarcely a single mental test that can be applied unequivocally as a 
psychical measuring-rod. The fact is we have not agreed upon 
methods of procedure; we too often do not know what we are 
measuring; and we too seldom realize the astounding complexity, 
variety, and delicacy of form of our psychical nature. 

Paradoxical as it may seem, these are the reasons, we believe, 
that render the elaboration of a scientific system of mental tests 
a possibility, for, if the all-too-evident lack of agreement in the 
results of the investigations already made is not attributable 
to faulty or divergent methods, or to clumsiness and ignorance,- — 
if, in other words, the discrepancies are inherent and ultimate, — ■ 
then we never can have a science of mental tests. 

What we need is not new tests, though they are welcome 
enough, but an exhaustive investigation of a selected group of 
tests that have already been described or proposed. In particular, 
we need more than anything else, at least from the point of view 
of application, the establishment of norms of performance for 
these tests, ^ — norms that are based upon investigations in which 
standard and prescribed methods of procedure have been fol- 
lowed in a rigid and undeviating manner. 

This book is an attempt to assist in the realization of this need . 
It presents a program of work, rather than a final system of 
results. 



CHAPTER II 
GioNKUAL Rules for tiik Conduct of Tksts 

The followinfi' general lulos may bo laid tlown at the outset. 

(1) The essential and funchmK^ntal principle underlying the 
conduct of scientific tests is the standardimtion of conditions. 
This does not mean that ex{)ensiv(^ a})i)aratus oi- instruments of 
precision are always necessary, but simph' that Ihe conditions 
under which a test is given to one jierson oi- to one g'roup of per- 
sons nuist l)e identically followed in iiiviuij; the same test to another 
|)erson or i^'rouj). We cannot always make the conditions ideal, 
l)ui^ we can at least try to keep them constant, if fh(^ conditions 
are vai'icMl, they nnist l)e varied intentionally and for a (h^finite 
purjios<'. 

(2) No detail in the 'setting' of a test is too trivial to 1)0 neglecteth 
This is, of course, merely a restatement of the ])i'evious principle 
in' another form. It is noteworthy that the lack of accordance 
between the results obtained by different investigators in the use 
of what is ostensibly the same test almost invariably turns out 
to be due to seemingly trivial variations in the method of adminis- 
tering the test. 

In particular, attention may be calliMl h(>r(^ to such mattei's as 
the time of day at which the experim(>nt is nia(l(>, the nature of 
the instructions that ]-)recede the test, the (Muotional attitude of 
the |)articipants toward the investigation, their ability exactlyto 
comprehend what is wanted of them (of wiiich more hereafter) 
and their willingness to do their best tbroughout the test. It is 
well to write out the preliminai-y instructions and to memorize 
t l\em, after fii'st making a trial in oi-der to see if they are perfectly 
intelligible. Thus, for instance, to say to one class of school 
childi-en: "Cross out all the r's on this ]iaper while I take your 
time with a watch," and to another class: "Cross out all the fi's 
on this pajuM- as fast as yi)u can" may mean the same thing to 



GENERAL RULES 5 

the experimenter, but it will not bring the same results from the 
classes under investigation, because in the second case the idea 
of fast work has been more strongly emphasized. 

(3) No test should be undertaken by the examiner, E, until he 
is perfectly familiar with its nature, its purpose and its administration. 
Especially if it involves the use of apparatus, he should familiar- 
ize himself with the manipulations until they become automatic. 

(4) No test should be undertaken until the subject, S, is per- 
fectly clear as to what is required of him. Since most mental 
tests are of an unfamiliar character, something beside explicit 
instructions, however clearly put, is needed to enable the avei-age 
*S to undertake the test under proper conditions. Ordinarily, 
a brief period (say 1 to 5 minutes) of fore-exercise is needed to 
remove timidity, excitement or misunderstanding. If this prelimi- 
nary exercise is propei-ly arranged (especially by being based upon 
material not usfnl in the test proper, and by being of the same 
length and character for all *S's), it does not introduce a serious 
practise error, while it does decidedly facilitate the test. In some 
cases, however, as, for instance, when the facility of adaptation to 
the test-conditions is itself an object of investigation, the fore- 
exercise should be omitted. 

(5) E should be on the look-out for external signs of the way in 
which S responds to the test, i. e., for indications of readiness, 
of quick comprehension, of a competitive spirit, or of ennui, 
fatigue, distraction, shift of attention, trickiness or deceit. The 
record -blanks should have a space for the recording of remarks 
of this nature. When tests are conducted individually it is 
surprising how much can be gleaned in regard to <S's mental 
traits by these indirect hints. In particular, whenever the object 
of the test is to examine the correlation of some physical or mental 
trait with >S's general intelligence, it is largely upon this sort 
of observational record that E must depend for his estimate of this 
general intelligence, even though the test be supplemented by 
school marks, the estimates of teachers, and similar devices. 

(6) Most mental tests may be administered either to individ- 
uals or to groups. Both methods have advantages and disadvan- 
tages. The group method has, of course, the particular merit of 
economy of time; a class of 50 or 100 chiklren may take a test 



THE CONDUCT OF TESTS 

in less than a fiftieth or a hundreth of the time needed to adminis- 
ter the same test individually. Again, in certain comi:»arative 
studies, e. g., of the effects of a week's vacation upon the mental 
efficiency of school children, it becomes imperative that all ;$'s 
should take the tests at the same time. On the other hand, 
there are almost sure to be some /S's in every group that, for one 
reason or another, fail to follow instructions or to execute the test 
to the best of their ability. The individual method allows Eio 
detect these cases, and in general, by the exercise of personal super- 
vision, to gain, as has been noted above, valuable information 
concerning <S's attitude toward the test. 

(7) One })hase of the group vs. individual procedure demands 
special attention, viz: the problem of time-control. In many, 
if not in most tests, efficiency is measured, at least m part, by 
the rate at which the assigned work is performed. Now, in 
theory, rate or speed might be measured either by the amount of 
work performed within a given time or by the time taken to per- 
form a given amount of work, in other words, by a time-limit 
method or by a work-limit method. In practise, however, we 
often find it difficult to arrange the material of a test in such a 
way as to make the task of equal objective difficulty at every por- 
tion of the test, and, even when this is possible, subjective varia- 
tions may appear because of the fact that different S's, accomplish 
different amounts of work. Theie is no doubt, therefore, that 
the work-limit method is to be preferred to the time-limit method: 
it is better, in other words, that every S should be asked to per- 
form the same work and to measure his efficienc)^ in terms of 
elapsed time than to require every S to work for the same time 
and to measure his ejQ&ciency in 'ground covered.' But the time- 
limit method is compulsory in all tests of this order undertaken by 
groups. 

(8) This leads naturally to a consideration of other tlifficulties 
that arise in scoring individual performance. Special difficulties 
are considered later in the discussion of the tests in which they 
appear, while the methods of handling measurements in general 
are treated in the following chapter. Attention is called here, 
however, to one fundamental problem, viz: the relation of quantity 
of work to quality of ivork. These two factors appear in nearly 



GENERAL RULES 7 

every test of mental efficiency, and the question aiises : shall efficiency 
be measured in terms of quality, excellence, delicacy or accuracy of 
work, or shall it be measured in terms of quantity, rate, or speed of 
work? To this question no general answer can be given. Roughly 
speaking, quantity and quality of work probably tend, at least for a 
given S, to be inversely related. Whenever this relation can be 
demonstrated, it is theoretically, and often, indeed, actually 
possible to convert the two measures into a single index of 'net 
efficiency,' — an index that is much desired for the study of general 
comparative relations. In other instances it has been proposed^ so 
to adjust the conditions of the test as to throw the emphasis so 
strongly upon quantity or upon quality of performance that the 
unemphasized factor may be neglected. In yet other instances, 
it seems necessary to keep both an index of quantity and an index 
of quality, and to make reference to both in subsequent compara- 
tive study. 

(9) In the application of any test, it is usual first to secure cer- 
tain preliminary data concerning S's personal history. Thus, 
in the experimental study of school children, E will find it advisable 
to record (a) name of the pupil in full, (b) sex, (c) date of bii'th, 
(d) name of school, (e) grade, (/) date, (g) hour. Other items, 
less uniformly recorded, but often of interest, are the following: 
(h) general health, (i) color of eyes and hair, (/) right or left- 
handedness, (k) name of teacher, (Z) names and address of parents, 
(m) nationality of parents, (n) date of birth of parents, (o) occupa- 
tion of parents, (p) number of children in family and their sex, 
(q) number of pupil in children of his family, (r) medical history of 
the pupil and his family, (s) obvious developmental defects or 
physical peculiarities, (t) details of personal habits, such as sleeping, 
eating, drinking, smoking, exercise, work, etc., (u) conduct in 
school, (v) proficiency in school work. 

In recording age it is best to note the exact date of S's birth. 
Unfortunately, direct comparison of the results of different inves- 
tigators has at times been rendered difficult on account of dis- 
parity in the method of recording age. Thus, in arranging statis- 

^For an illustration of both of tliese methods for obtaining a single index, 
see the Cancellation Test. 



8 THE CONDUCT OP TESTS 

tical tables, a boy 9 years and 7 months old would by some be 
classed in the group of 9-year olds, by others in the group of 10- 
year olds, as being nearer 10 than 9. A third method, which 
has the advantage of 'being clear to the reader and not confusing 
to E, is to put all *S's at or past a given birthday into a single 
group, the age of which is specified as that birthday, plus a half- 
year, e. g., all *S's between their 9th and 10th birthday comprise the 
9.5 year-old group, since their average age tends, of course, to 
approximate 9.5 years. 



CHAPTER III 

The Treatment of Measures 

The immediate results of the application of mental and physical 
tests are very apt to be obscure or unintelligible until they have 
been ordered and systematized by proper statistical treatment. 
It is the purpose of the present chapter to explain the most common 
methods by which this systematization is accomplished. ^ 

A. measures of general tendency 

In many cases it is unnecessary, if not impossible, to keep m 
view the individual measurements of an extended se/ies. We 
naturally seek to condense these values into a single represen- 
tative value. Any single measure that affords us such a summary 
of a series of measurements may be termed a 'representative 
measure' or a 'measure of general tendency.' There are three 
such measures in common use,— the average or mean, the median, 
and the mode. 

1. The Mean. 

(a) The ordinary arithmetical mean (M), more often termed 
the average in psychological measurements, is computed by divid- 
ing the sum of the several measurements or magnitudes (m) l)y 
their number (n). 
•Hence: 

M ^ — . (1) 

n 

■ The reader will find more extended discussions of measurement methods 
in the following: Galton, Thoriidike, Titchener, Sanford, Wissler, Spearman, 
C. B. Davenport, E. Davenport, Merriman, and Elderton (see the end of this 
chapter for exact references). Technical papers upon correlation formulas 
by Pearson, Yule, and others will be found in various numbers of Biometrika, 
the Proc. of the Royal Sac. of London, and in the Phil. Transactions of th»j 
same body. 



10 



THE TREATMENT OF MEASURES 



TABLE I 
Strength of Grip, in Hectograms, 50 boys (^Whipple) 







RIGHT HAND 




LEFT HAND 




RANK COMPARISONS 


i 


KO. 


STAND- 
ING 


d 


</•■•' NO. 


STAND- J 


d' 


G 


D 


D- 


XV 


1 


30 


15S 


-125 


15625 30 


138-135 


18225 











16740 


2 


17 


175 


-108 


11664 17 


163-110 


12100 


— 








IISSO 


3 


52 


193 


- 90 


8100 1 


175- 98 


9604 





6 


36 


7470 


4 


39 


197 


- SQ 


7396 48 


180- 93 


8649 


— 


2 


4 


7568 


5 


10 


197 


- 86 


7396 7 


180- 93 


8649 


— 


9 


81 


5246 


6 


43 


200 


- 83' 


6889 39 


1S5- 88 


7744 


— 


2 


4 


6889 


7 


1 


205 


- 78 


6084 16 


190- 83 


6889 


4 


4 


16 


7644 


8 


40 


206 


— 77 


5929 43 


190- 83 


6889 


— 


4 


16 


5236 


9 


3 


208 


— 75 


5625 52 


190 - 83 


6889 


— 


1 


1 


5550 


10 


7 


210 


- 73 


5329 3 


199- 74 


5476 


5 


5 


25 


6789 


11 


6 


210 


- 73 


5329 6 


200- 73 


5329 


_. 








5329 


12 


4S 


220 


- 63 


3969 40 


205- 68 


4624 


8 


8 


64 


5859 


13 


42 


225 


- 58 


3364 15 


210- 63 


3969 


— 


6 


36 


2204 


14 


2 


225 


- 58 


3364 10 


212- 61 


3721 


— 


2 


4 


2842 


15 


19 


225 


- 58 


3364 19 


215- 58 


3364 


— 








3364 


16 


37 


226 


- 57 


3249 2 


224- 49 


2401 


— 


10 


100 


741 


17 


15 


235 


- 48 


2304 50 


235- 38 


1444 


4 


4 


16 


3024 


IS 


vj 


244 


- 39 


1521 8 


235- 38 


1444 


— 








1482 


19 


14 


244 


- 39 


1521 42 


235- 3S 


1444 


_ 


6 


36 


507 


20 


51 


245 


- 38 


1444 23 


242- 31 


961 


— 


1 


1 


1102 


21 


50 


24S 


- 35 


1156 51 


244- 29 


841 


4 


4 


16 


1330 


22 


41 


262 


- 21 


441 45 


245- 28 


784 


— 


2 


4 


273 


23 


25 


262 


- 21 


441 9 


253- 20 


400 


— 


14 


196 


-735 


24 


23 


267 


- 16 


256 41 


260- 13 


169 


4 


4 


16 


496 


25 


12 


269 


- 14 


196 14 


260- 13 


169 


— 


5 


25 


- 98 


26 


44 


270 


- 13 


169 37 


260- 13 


169 





1 


1 


78 


27 


29 


273 


- 10 


100 44 


267- 6 


36 


— 


2 


4 


- 20 


28 


9 


280 


- 3 


9 34 


270- 3 


9 


5 


5 


25 


60 


29 


45 


290 


J- 7 


49 29 


275 + 2 


4 


7 


7 


49 


-196 


30 


36 


294 


11 


121 12 


2S0 7 


49 


— 


10 


100 


594 


31 


11 


296 


13 


169 32 


2S2 9 


81 


— 


3 


9 


312 


32 


2S 


301 


IS 


324 20 


290 17 


289 


— 


4 


16 


576 


33 


32 


310 


27 


729 13 


290 17 


289 


2 


2 


4 


243 


34 


31 


313 


30 


900 11 


297 24 


576 





1 


1 


810 


35 


20 


315 


32 


1024 31 


300 27 


729 


3 


3 


9 


544 


36 


34 


320 


37 


1369 - 28 


305 32 


1024 


8 


8 


64 


- Ill 


37 


24 


323 


40 


1600 ! 25 


308 35 


1225 


— 


4 


16 


2520 


3S 


16 


325 


42 


1764J 26 


315 42 


1764 


31 


31 


961 


-3486 


39 


35 


330 


47 


2209 38 


325 52 


2704 





3 


9 


3854 


40 


13 


346 


63. 


3969 36 


327 54 


2916 


7 


7 


49 


1071 



MEASURES OF GENERAL TENDENCY 



11 



TABLE I (Continued) 





RIGHT HAND 




LEFT 


HAND 




BANK 


COMPARISONS 


Q 
O 


NO. 


STAND- 
ING 


d 


d^ 


NO. 


STAND- 
ING 


d 


i2 


G 


D 


d2 


xy 


41 


38 


348 


65 


4225 


24 


336 


63 


3969 


2 


2 


4 


3380 


42 


46 


350 


67 


4489 


35 


355 


82 


6724 





3 


9 


7035 


43 


33 


353 


70 


4900 


49 


362 


89 


7921 





1 


1 


7140 


44 


26 


375 


92 


8649 


33 


375 


102 


10404 


6 


6 


36 


3864 


45 


21 


375 


92 


8649 


46 


378 


105 


11025 


— 


2 


4 


12236 


46 


18 


403 


120 


14400 


18 


400 


127 


16129 











15240 


47 


27 


430 


143 


20449 


21 


406 


133 


17689 


— 


2 


4 


25311 


48 


49 


440 


153 


2,3409 


5 


443 


170 


28900 


5 


5 


25 


13617 


49 


5 


440 


153 


23409 


27 


450 


177 


31329 


1 


1 


1 


26010 


50 


22 


508 


221 


48841 


22 


490 


217 


47089 


— 








47957 


Sums 


14164 


3088 


287884 




13651 


3166 


315223 


106 




2098 


277371 


Aver... 


283 


61.4 


5757.7 




273 


63.3 


6304.4 











r^yf.-^^^ 



TABLE 2 
Values Derived frntn the Data of Table 1 





FORMULA 


VALUE 




Right Hand 


Left Hand 


Mean 

Median 


1 

3 

4 

5 

6 

7 

10 

11 

12 

13 

16 


283.0 
269.5 

61.4 ^ 

75.8 

76.5 

76.9 

51.1 

51.6 

50.7 

51.9 
0.27 


273.0 

260.0 

63.3 

79 


A.D 

S.D 


S.D 

S.D 


80.2 
79 3 


P.E 


53 3 


P.E 


54.0 
52 


P.E 


P.E 


53 5 


C 


'^9 







12 THE TREATMENT OP MEASURES 

The mean is the most familiar measure of general tendency, 
and it is the most precise, because it is affected by all measurements 
in proportion to their size. It has, however, some disadvantages: 
its computation requires more labor than that of the median or 
the mode,* and, as will be shown later, it may fail after all to afford 
a truly representative value. Examples of arithmetical means are 
scarcely needed, but may l^e found in Tables 1 and 2, and else- 
where. 

(b) The v^eighted arithmetical mean is serviceable as a short 
cut in dealing with a large number of measures. Its use may be 
made evident by the following hypothetical case. Suppose it 
were desired to ascertain the average height of 1000 12-year old 
boys. By the ordinary method we should be obliged to record 
each measure exactly (say, within 1 mm.) and to add the entire 
1000 measurements. To utilize the weighted arithmetical mean, 
we divide the range of height into a limited number of groups of, 
let us say, 2 cm., and record simply the number of cases that fall 
into each group, i. e., the frequency of each group. Thus in Table 
3, there are in the 6th group 88 measurements lying between the 
limits 135 and 137 cm. The weighted mean can now be found 
very simply by multiplying the value or magnitude representing 
each group bythe corresponding frequency (1 X 126, 5 X 128, etc.) 
and dividing the sum of the products by the sum of the frequencies 
(1000). 

The formula for the weighted arithmetical mean is therefore: 



M 



^ (m ■ /) 
-^7 ' 



M = ^i!-^- (2) 

n 

It is clear that this weighted mean approaches the ordinary 
mean in accuracy in proportion as the number of classificatory 
groups is increased. 

* The computation of M may be greatly lessened by assuming a convenient 
approximate value, and correcting subsequently to the true value. For illus- 
trations, see Davenport (4, p. 429) or Thorndike (21, p. 71). 



[EASURES OF GENERAL TENDENCY 



13 



TABLE 3 
Distribution of the Heights of 12-Year Old Boys {Hypothetical) 



Centimeters 


126 


128 


130 


132 


134 


136 


138 


140 


142 


144 


146 


148 


160 


152 


154 


156 


158 


160 


Deviation . . 
Frequency. 


-16 

1 


-14 
5 


-12 
14 


-10 
24 


-8 
39 


-6 

58 


-4 
96 


-2 
120 



150 


2 
142 


4 
123 


6 

88 


8 
63 


10 
36 


12 
23 


14 
12 


16 
5 


18 
1 



Weighted mean = 142.9 Median = 143.4 Mode 



142. 



2. The Median. 

The median or central value is, literally, the mickllemost of 
&. group of measurements arranged singly in ascending or descend- 
ing order, or the measure above and below which lie an equal 
number of individual measurements. It is expressed, thei-efore, by 
the formula: 



median 



the 



n + 1 



measurement 



(3) 



(t...^ p. 



In practise the median may or may not coincide with some 
actual measurement; more often than not it is an interpolated 
value. To compute its value we must first arrange the measures 
serially (if any magnitude is repeated two or more times, the 
number of such repetitions must, of course, be indicated). To 
find the middlemost measure when interpolation is needed, we 
may proceed by a simple method which may be illustrated by 
reference to Table 3. Here the first 8 groups (126 to 140 cm.) 
represent 357 measurements; since there are 1000 measurements, 
the middlemost measurement lies in the ninth group of 150 cases: 
the value desired is, therefore, the theoretical value between the 
143d and the 144th measurement in this group. We have, there- 
fore, to take '— of the range of magnitude covered by the 9th 

group (2 cm.), and add this to the lower limiting value of the 
group, 141.5 cm., so that we obtain for the median the value, 
141.5 + 1.9, or 143.4. 

The gi-eat merit of the median is the ease with which it can 
be determined: in short series it is not even necessary to arrange 



ti< 



c> 



14 THE TREATMENT OF MEASURES 

the measures serially, as one-half of the measurements may be 
checked off by inspection. Its primary disadvantage is that it 
gives little -weight to extreme deviations and may fail entirely 
to represent the type, yet, in many psychological observations, 
it is precisely these extreme deviations which are most suspicious, 
so that this tendency of the median to lessen the significance of 
extreme, measures may prove a positive advantage. 

In general, the longer the series or the more homogeneous the 
values, the more nearly does the median approximate the mean. 

S. The Mode. 

If a numl)er of measurements are distriljuted in ascending or 
descending order, a mode is a measure that appears more frequently 
than do measures just above or below it in the series. There may 
be several modes in a distribution, though usually there is but 
one, and we may therefore define the mode as the commonest 
single value, or the commonest condition. 

Many statistical arrays find a better representative value in the 
mode than in the average. Thus, when we speak of the ''average 
American citizen," we really have in mind the typical citizen, 
the one most frequently met with. To borrow an illustration 
from Rietz (4, p. 684): " If a community has 10 millionaires, but 
all the other citizens are in poverty, an arithmetical average might 
give the impression that the people of the community are in good 
financial condition, while really the 'aveiage citizen' is in poverty. " 
The primary use of the mode is therefore, to characterize a type. 

Strictly speaking, we may have an empirical mode, as indicated 
in a given array and a theoretical mode, which would be the most 
frequent condition in a theoretical distribution. The latter is 
difficult to compute and not often employed. If an array is very 
irregular, there is, in strictness, no mode or type at all, or at 
least the indicated mode has little significance. 

In Table 3, it is clear that the mode is 142 cm., because this 
measure appears 150 times, and no other measure is as frequent. 



MEASURES OF VARIABILITY 15 

B. MEASURES OF VARIABILITY 

It is a common fallacy to rest content with the statement of 
the general tendency of measurements. Even in supposedly 
accurate and scientific determinations, we may find the quantita- 
tive expression limited to averages, e.g., "the mean temperature 
for September," "the average weight of 12-year old boys," etc. 
But it is evident that the average gives no indication of the dis- 
tribution of the individual measures from which it is obtained, no 
indication of the extent to which these measures vary or deviate 
from the average, no information as to how homogeneous is the 
material that the average represents. The September temper- 
ature may have been seasonable and equable or there may have 
been some days of frost and some days of sweltering heat. Again, 
if five individuals weigh 80, 65, 60, 40, and 55 kg., respectively, 
and five others 62, 59, 60, 51, and 58 kg., respectively, then the 
mean weight of either group is 60 kg., but one group is distri- 
buted very closely around the mean, whereas the other group 
exhibits such marked deviations from it that M (or any other gen- 
eral tendency measure) has little or no significance as a repre 
sentative value. 

From this it follows that we need not only measures of general 
tendency, but also measures of the variability or tendency to 
deviation of measurements, and that these latter are of well- 
nigh equal importance. 

There are three common measures of variability, ^ — ^the average 
deviation, the standard deviation, and the probable error." 

1. The Average Deviation {Mean Variation) 

To find the average deviation we must first find the mean, M, 
(or median or mode); second, substract each individual measure 
m, algebraically from M , which gives a series of deviations, d; 

^ Besides these measures, range of variability is sometimes indicated roughly 
by stating the maximal and minimal measurements, in conjunction with M. 
This gives us, at least, information as to the extremes of deviation. 

^ ft is well to avoid confusion here at the outset. The average deviation 
(A. D.), as used by the statisticians, is identical with the mean variation (m. 
v.) of experimental psychology. The standard deviation {o) is called the 
average error by Sanford, the mean error by Merriman, and the error of mean 
square by others. 



16 THE TREATMENT OF MEASURES 

third, find the average of these deviations, i. e., the mean of the 
variations, by summating without reference to sign and dividing 
by the number of cases. 
Hence: 

A.D. or m.v. = ^ ~ ^ ^ ^ -i 



A.D. 



d, + ^2 + ■■ dn 



n 



A.D.--^-' (4) 

n 

Reference to Table 1 will render this i)rocess clear: there the 
average right hand grip is 283; the weakest boy has a standing 
of 158, hence he deviates 125 units from the average; the first 
28 boys rank below average and therefore exhibit minus devia- 
tions, the rest are above average and exhibit plus deviations; 
all these deviations are added without regard to sign and 
their sum, 3088, is divided by the number of cases, 50, yielding a 
mean variation of 61.4 hectograms. If the median were selected 
as the representative value, the variability would, of course, be 
computed similai-ly witii a new series of rf's. 

2. The Standard Deviation {Error of Mean Square) 

This measure of variability is preferred by many experimenters 
and is practically the only one employed by statisticians, as it is 
thought to be more accurate than the average deviation, but it 
is much more laborious to compute. It is the square root of the 
average of the squares of the individual deviations 



S. D., or o 



I d' +d: + dl+ ... d\ 



J^^. (5) 



MEASURES OF VARIABILITY 17 

If n is small, the formula is often modified by wi-iting n-1 in 
place of n:i 
Hence: 






(6) 



The application of Formula 5 is illustrated in Table ], 5th 
and 9th columns, whei-e the squares of the individual deviations 
arc shown in detail. The sum of these squares foi the right-hand 
grip is 287,884. This is divided by 50, giving 5757.7, the square 
I'oot of which is 75.8, the a desired. 

The S. D. of a given series is somewhat larger than its A. D. 
Theoi-eticall}^, and practically if the distribution he symmetrical 
and the observations sufficiently numei-ous, the relation is constant 
at 

(7 = 1.2533^.2). (7) 

Conversely, 

yl.Z). =0.7979 (7. (8) 

As shown in Table 2, the S. D. computed by Formula 7 is 
closely similar to that computed by Formula 6. 

3. The Probable Error 

The probable error of a single measure (P. E.) is a measure of 
the limits above and below M (or other representative measure) 
that will include one-half of the individual measures; in other 
words, it is a value such that the number of measures that exceed 
it is the same as the number of measures that fail to reach it. 2 

'For the reasons for tliis substitution, consult Merriman (p. 71). It is 
evident that the effect of the substitution becomes progressively less as n 
increases: as will be seen in Table 2, the difference between Formula 5 and 
Formula 6 is practically negligible when n = 50. 

^ The term 'probable error' is often a source of confusion to those unfamiliar 
with its use in mathematics. The magnitude in question is not, of course, 
the most probable error, neither is it, from our point of view, an 'error' at all. 
For a descriptive term, we might call the probable error the median deviation 
since it is that deviation that is found mitlway from the representative value 
in either direction. 



18 THE TREATMENT OF MEASURES 

The P. E.is appi-oximately two-thirds the S. D., or more exactly. 
P. E. = 0.6745 a. (9) 

]^y reference to Formula 5 this becomes: 

P.E. = 0.6745 J^-^' (10) 

^^ n 

or, for a small miml^er of cases (Formula 6): 

P.E. = 0.6745 JA-^^I". (11) 

^ n- 1 

In practise we may find the P. E. approximately, if the dis- 
tribution be assumed to be normal (see under D, below), by count- 
ing off one-fourth of the cases from either end of a series of measure- 
ments, and halving the difference between the two values thus 
found. 

P.^. = ^--~^^" > (12) 

Thus in Table 1, these limits lie at the 12th and a half and the 
37th and a half measurements, and have, for the right-hand grip 
the values 222.5 and 324, respectively; hence, P. E. =324 - 
222.5 -=- 2 = 50.7, — a value that is approximately the same as 
the values of P. E. computed by Formulas 10, 11 , and 13 (Table 2). 
By Formula U, P. E. = 0.6745 X 76.5 =51.6. Corresponding 
values are given in Table 2 for the left-hand grip as distributed 
in Tal)le 1. Still other values might be computed on the basis of 
the median instead of the mean. 

By combination of Formulas 7, S, and 9, we may olitain for 
a normal distril)ution: 

P.E. = 0.8453 A.D. (13) 

S. D.= 1.4825 P.E. (14) 

A.D.= 1.1843 P. E. (15) 

The first of these is illustrated in Table 2. 



GRAPHIC REPRESENTATION 19 

4. The Coefficient of Variability 

If it is desired to compare the variability of one series of measure- 
ments with that of another, it will be found that, as a rule, their 
respective measures of variability cannot be compared directly, 
because they are based upon different units or at least upon dif- 
ferent measures of general tendency, but the relations of the two 
measures of variability to their respective measures of general tend- 
ency can be directly compared. In other words, we can com- 
pute two coefficients of variability (C) by dividing in each serifes 
a measure of variability by a representative measure, i. e., either 
S. D., A. D., or P. E., may be divided by either mean, median, 
or mode. Unless otherwise specified, it may h& assumed that S. D. 
is divided by M. 
Hence: 

C=^ (16) 

M 

Thus, in Table 1, for strength of right hand, C = 76.5 - 283 = .27 
and for strength of left hand, C = 80.2 -^ 273 = .29, hence the 
latter series is slightly more variable. 

C. THE GRAPHIC REPRESENTATION OF MEASUREMENTS 

A series of measurements, as we have seen, can be expressed 
adequately by a single representative value only when that value is 
accompanied by some measure of variability. Even these two 
values may fail to express the series completely, since they aire, 
after all, only symbols for the convenient summarizing of general 
tendency and variability, whereas a complete numerical expression 
of a series of measures would imply the tabulation of all the data 
of the series. Such a tabulation is for the most part impracticable, 
or at least of little significance, because of the difficulty of grasp- 
ing the nature of the series by the inspection of a mass of figures. 

The use of the graphic method, however, supplies a most ser- 
viceable- and effective means of showing at a glance all of the 
important features in the distribution of a series of measurements 
and likewise of relations between series of measurements. 



20 THE TREATMENT OF MEASURES 

1. The Plotting of Frequencies or Graphs of Distribution 

The most usual form of graph for iUustrating the distiibution 
of a series of measurements is constructed as follows: 

Draw two lines, OY and OX (Fig. 1) in the form of coordinate 
axes, i. e., with OF perpendicular to OX. Upon the horizontal, 
or a:-axis, lay off convenient intervals corresponding to the units 
of measurement of the series to be plotted; upon the vertical, 
or y-axis, lay off intervals corresponding to the frequencies of the 
series. 

The choice of the scale units is largely arbitrary. The intervals of the two 
axes need not be the same, nor need different graphs, save for purposes of 
direct comparison, be plotted to the same scale. In general, a scale should 
be selected that will bring the surface easily into view as a whole and that will 
render conspicuous the features that are under consideration. Thus, if one 
is studying rate of increase or decrease, a scale should be selected that affords 
a fairly steep curve in order to emphasize its rise and fall. 'Squared' or cross- 
section paper (usually laid off by mm. on sheets 15 x 20 cm.) may be purchased 
for curve-plotting, and will be found invaluable for this work. 

In illustration, the numerical table of frequencies above (Table 
3) is turned into a surface of frequency upon the axes just men- 
tioned (Fig. 1). We mark off on the x-axis, it will be seen, 18 
equal intervals corresponding to the range of dimensions, 126, 
128, . . . 160 cm. Uponthe?/-axis we mark off equidistant intervals 
for the range of frequencies from 1 to 150. We next locate the 
series of 18 points. The first point lies vertically above the 126 
cm. mark at a distance equal to 1 of the vertical units; the second 
lies vertically above the 128 cm. mark at a distance equal to 5 
vertical units, etc. By joining the 18 points thus located, the 
resulting line evidently gives in a single visual impression the 
distribution that was expressed numerically in Table 3. Any 
point in this line is fixed by stating its abscissa or distance from the 
y-axis, and its ordinate, or distance from the rc-axis.^ 

Now it would have been equally feasible to have considered the val- 
ues in Table 3 in terms of their deviation from the mean, median or 
mode, and with little or no change in the curve. Take, for simplic- 

* The 'curve' is sometimes so drawn as to form the tops of a series of columns 
erected at the intervals on the base-line, instead of by joining the single points 
as here described. See, for illustrations, Thorndike (21, p. 48, or 20, p. 15). 



GRAPHS OF DISTRIBUTION 



21 



ity, the mode, 142 cm., as the representative value. Erect an ordi- 
nate of the value of 150 at a point M on the a:-axis (Fig. 1) ; inter- 
vals to the right of this ordinate may now represent positive 
deviations ( -f 2, + 4, + 6, etc.) while those to the left represent 
negative deviations ( — 2, — 4, —6, etc.), as indicated in Table 3. 
It thus becomes possible to represent negative values graphically. 



Y 

Tl60 



126 III ISOi 

FIG. 1. GRAPHIC REPRESENTATION OF THE DISTRIBUTION OF TABLE 3. 



2. The 'Smoothing' of Distributions 

Ordinary measurements are subject to numerous disturbing 
factors; our units of measurement are often coarse; our oppor- 
tunities for securing data are always restricted; variable factors 
of one sort or another obtrude themselves, — and these disturbances 
produce irregularities in the resultant data. The obtained dis- 
tribution, in other words, does not coincide with the true distri- 



22 



THE TREATMENT OF MEASURES 



bution, i. e., with the distribution that would theoretically appear 
under ideal conditions. Thus, in Table 3, chance may have led 
to the measurement among the 1,000 cases studied, of more 
boys of a certain height, say 144 cm., than we should ordinarily 
have encountered in measuring 1,000 pupils taken at random. 
Or, to take an instance of a striking artificial distortion, in the 
census returns, people who are 39 or 41 years of age show a tend- 
ency to report their age as 40, so that the age of 40 has an un- 
naturally large frequency. 

Minor deviations from the theoretically expected distribution 
may be counteracted if we are constructing a frequency graph by 
'smoothing' the curve, i. e., by drawing the connecting line in 
the form of a true curve rather than a broken straight line: such 
a curve will pass in the neighborhood of the several points which 
have been located by the numerical data, but will not necessarily 
pass exactly through these points. The result is a graph that shows 
how the data would presumably have been distributed if the 
factors which produced the distortions and irregularities were 
eliminated. 

TABLE 4 



The Numerical 


Smoothing 


o/ the Distribution 


of 


Table 3 








Centimeters 


126 


128 


130 


132 


134 


136 


138 


140 


142 


144 


146 


148 


150 


152 


■" 


156 


us 


160 


Original . . . 
Smoothed . 


1 
2 


5 
6 


14 
14 


24 
26 


39 
40 


58 
64 


96 
91 


120 
122 


150 
137 


142 
138 


123 
108 


88 
91 


63 
62 


36 
41 


23 

24 


12 
13 


5 
6 


1 
2 



■ In tabular work these deviations may be counteracted by a simple 
arithmetical process. Replace each frequency except the two 
extreme ones by the mean (to the nearest integer) of the given 
frequency and the one just below it and the one just above it; 
replace the two extreme frequencies by the mean (to the nearest 
integer) of the given frequency taken two times and the adjacent 
frequency taken once. If necessary, a second smoothing may be 
made of the values obtained by the first smoothing. 

The values of Table 3 do not exhibit marked irregularities as 
is evident from their graphic distribution in Fig. 1 : the process of 
Smoothing may, however, be illustrated by the treatment in 
Table 4. 



NORMAL DISTRIBUTION 23 

D. NORMAL AND OTHER TYPES OF DISTRIBUTION: THE PROBA- 
BILITY SURFACE AND ITS APPLICATIONS 

1. The Normal Frequency Surface 

Assume that errors of observation have been ehminated and 
that a large number of measurements of some psychological 
trait or capacity have been secured: experience has shown, and 
theoretical considerations likewise indicate, that as a rule these 
measurements will distribute themselves in the form of a symme- 
trical bell-shaped curve, variously known as the probability curve, 
the curve of error, Gauss' curve, or the normal frequency surface, 
— the salient characteristics of which are a maximal frequency at 
M with a series of positive and negative d's, from M that are 
symmetrically disposed on either side of it and whose frequency 
decreases progressively as their size increases. 

Such a distribution implies the operation in the conditions that 
underlie the feature or trait under measurement, of an indefi- 
nitely large number of individual factors, each of which is equally 
likely to be present and effective. When, however, there are limiting 
or restricting conditions, or when one or more factors are present 
oftener than mere chance would allow, the resultant distribution 
will tend to depart from the normal type. Thus, the chances of 
death at different ages are not distributed according to the normal 
curve, but are higher in infancy and old age than in youth and 
middle age. The mental ability of college students is not likely to 
be distributed like that of the non-college population of the same 
age on account of the selective influence of entrance requirements.^ 
In general, distributions that do not conform to the normal type 
are termed 'skewed' distributions, and may demand special 
mathematical treatment. 

2. Relation of the Normal Curve to S. D. and P. E. 

The normal surface of frequency has interest still further 
because in it the significance of P. E. and of S. D. becomes clear. 
In fact, the latter bears to the curve a relation like that of a radius 

' On the application of the normal curve to the grading of college students, 
see M. Meyer (11). 



24 



THE TREATMENT OF MEASURES 



to its circle. If *S. D. is small, the measurements are relatively 
homogeneous and the curve is steep and compact (right-hand 
curve in Fig. 2), whereas, if S>. D. is large, the curve is broad and 
of easy slope (left hand curve in Fig. 2). If M and S. D. are 
known, the entire curve for a normal distribution is known. If 
the distribution is not of the normal form, the S. D. still remains 
a good measure of its variability, though not completely descrip- 
tive of the entire distribution.^ 

The geometrical explanation of the P. E. is simple. In Fig. 
2 we draw the ordinates ah and cd equidistant from OY and at 
such a distance that the area obYcd is equal to the remainder of 
the total area under the curve: then the abscissa Oa or Od repre- 
sents the value of P. E., i. e., a deviation from the mean that will 
include one-half the total deviations. 





a. O d «x O d 

FIG. 2. TYPICAL CURVES OF NORMAL DISTRIBUTION. 



3. P. E. of M and of Other Measures 

Since our opportunities for securing data are limited, it follows 
that even averages may fail to be absolutely exact measures of 
the general tendency of the trait under measurement. To revert 
to the hypothetical data of Table 3, we were there able to obtain an 
M, 142.9 cm., of the height of 12-year old boys: it must be evident 
that if we could have measured a million boys we should feel 



' This mathematical relation of S. D. to the probability curve, together witli 
the possibility, as is shown later, of determining many other features of th(i 
distribution from the relation of aS. D. and M, is one of the principal reasons 
why S. D. is preferred by many to the more-easily calculated A. D. 



THE PROBABLE ERROR 25 

surer that the M then obtained was the true one, or that if we had 
measured only ten boys of that age we should not have felt at all 
sure that the average thus obtained was truly representative of the 
height of 12-year old boys. We need, therefore, a measure of 
the reliability of M, so that we may have some idea as to how far 
the actually obtained M is likely to differ from the ideal or true 
M, or, reversely, how many measurements we need to secure an M 
that will have any desired or assigned degree of reliability. 

The most common measure of the reliability of M is afforded by 
its P. E., for there can be a P. E. of M as well as a P. E. of a 
single measurement or observation. To illustrate, suppose we 
did measure 1,000,000 boys in 1000 groups of 1000 measurements 
each; if we then averaged each group we should obtain 1000 M's, 
each representing the central tendency of a group chosen by ran- 
dom sampling: we should then expect these 1000 M's to be closely 
similar, but not identical, and we could distribute them like a 
series of individual measures and determine the P. E. of this 
distribution. In practise, the P. E. of M is found by a formula 
that takes into consideration the variability of the distribution 
which M represents and the number of cases on which it is based. 
This formula is 

P.^..= ^^^. (17) 

V n 

That is, the P. E. of M is found by dividing the P. E. of a single 
measurement (Formula 9) by the square root of the number of 
measurements. 

To bring this formula into relation with A. D., we may use the 
approximate formula 

P.E.^==^^-MB=A.D. (18) 

y^n- 1 

The consistency of a series of measurements may also be indi- 
cated by stating the degree of probability that will attach to the 
appearance of an 'error' or deviation or residual, as it is often 
termed, of a magnitude equal to any assigned multiple of P. E. 
By definition, a deviation of the magnitude of P. E. is one as Ukely 
to be exceeded as not; in other words, the chances are even, or 



26 THE TREATMENT OF MEASURES 

one to one, that it is exceeded. The probabiUty of the occurrence 
of a deviation several times as large as P. E. is, however, very 
much smaller, as will be seen in the following comparisons between 
P, the theoretical probability and X -^ P. E., multiples of P. E., 
from 1 to 5.^ 



- P.E. 




P. 


1 


1 - 


1.0 


2 
3 




5.6 
- 23.2 


4 


1 - 


- 143.3 


5 


1 - 


- 1342.2 



Besides the P. E. of m and of M, we may determine, by appro- 
priate formulas, the P. E. of measures of variability : two of these 
are given below; the application to measures of relationship will 
be discussed later. 

The P. E. of the S. D. is found by the formula 

P.E.= ^'^'''^ (19) 

\/2 

which, by reference to Formula 18, becomes 

P. £..04745. ,20) 

V2n 

^ These values are computed by reference to standard tables of values of 
the probability integral corresponding to various multiples of P. E. A con- 
densed table of this sort is published by Thorndike (21, p. 149). The values 
given above were derived for the author by Prof, G . C. Comstock of the 
University of Wisconsin from Oppolzer's 10-figure table of the Gamma Integral, 
and are correct to the first place of decimals given. To illustrate from Thorn- 
dike's condensed table; the total area of the probability surface being 1000, 
the total area representing deviation in either direction is 500. From the 
table we see that a deviation or residual equal to 3 P. E. occurs in such a 
manner that 479 of the 500 cases are included between it and the average or 
median, and hence it is exceeded by 21 of 500 cases, or by 1 case in 23.8, approx- 
imately; 23.2 when more accurate integral tables are used. 

From such a scries of values the consistency of the determination may be 
stated in various ways. For example, if a correlationof .50 was accompanied 
by a P. E. of .10, it might be said that the chances would be but 1 in more 
than 1300 times that such a correlation would occur by mere chance. 



MEASURES OF CORRELATION 27 

The p. E. of the coefficient of variabihty may be found approx- 
imately, if C is not greater than 10 per cent, by the formula 

P.g.,^ 67450^ (21) 

but more accurately, for any value of C, by the formula 



^^ 0.6745Cr^^^/C 
^/2n L ^00,' 



If.. Other Applications of the Probability Curve 

Since, when the distribution is normal, the surface of frequency 
is determined by M and S. D., we may, by reference to suitable 
tables, ascertain (1) the frequency of any deviation, (2) the range 
of deviation that will include any given percentage of w's, (3) the 
chances that the true M will differ from the obtained by any given 
amount, (4) the range of divergence of the true from the obtained 
M that corresponds to any given degree of improbability, and (5) 
in general, the degree of reliability, or unreliability, of the several 
measures of variability or relationship.' 

E. MEASURES OF CORRELATION 

1 . The Meaning of Correlation 

Physical science discovers numerous uniformities or corre- 
spondences between natural phenomena which are formulated as 
'natural laws': biological science, on account of the intricacy of 
the factors which condition vital phenomena, can discover, fop 

1 All of these calculations are made in terms of a probability integral 
table, which indicates for any normal surface the proportionate area of the 
probabiUty surface that is represented by any given degree of deviation 
(measured in this case in terms of the *S. D. of the distribution) . Lack of space 
precludes the discussion and reproduction of this table, which may be found 
in nearly all works on probability and statistics, e. g.-, Merriman (p. 187), C. 
Davenport (p. 55), Scripture, New Psychology, p. 475, Thorndike (21, p. 148; 20. 
p. 168). Examples of the calculations mentioned may be studied in Thorn- 
dike (21). 



28 THE TREATMENT OF MEASURES 

the most part, only tendencies to uniformity or tendencies to corre- 
spondence. Such a tendency of two or more traits or capacities 
to vary together is termed a correlation. Thus height and weight 
are obviously correlated because in general tall people are heavier 
than short people, but, of course, this tendency to correspondence 
is far from absolute, like the correspondence between the distance 
and speed of a body falling in vacuum or between the electrical 
constants, voltage, amperage and resistance as expressed in Ohm's 
law. 

Since in practically every psychological test we are searching 
for these tendencies toward correspondence, it is important to know 
how they can be measured. In not a few psychological inves- 
tigations correlation has been expressed merely descriptively as 
'fair,' ' large, '' poor, ' etc., and these characterizations have been 
derived from mere inspection of arrays of data. As a matter 
of fact, some of these published statements of correlation are actu- 
ally wrong: correlations do not exist where they have been affirmed, 
or do exist where they have been denied. At the present time 
there is no excuse for such merely descriptive statements of corre- 
lation, since, by the use of appropriate mathematical procedure, 
a tendency toward correspondence may be measured and expressed 
by a single quantitative symbol that has as much significance and 
definiteness as M, S. D., or any other statistical constant. This 
symbol, r, which sums up the proportionality or degree of relation- 
ship between two factors or events, is known as the index or co- 
efficient of correlation. 

Complete positive or direct correlation between two traits is 
present when the existence of the one is invariably accompanied by 
the existence of the other, or when increase of the one is invariably 
accompanied by corresponding and proportional increase of the 
other. 

Complete negative or inverse correlation is present when two 
traits are mutually exclusive, or when increase in the one is invari- 
ably accompanied by a corresponding and proportional decrease 
in the other. 

A correlation is indifferent or zero if the existence or variation 
of one trait is totally unrelated to that of the other. 

In perfect positive correlation, r is unity or 1.00; in complete 



THE PEARSON METHOD 20 

negative correlation, r is — 1.00; indifference or complete absence 
of correlation is 0. In actual psychological investigation, at 
least when functional correspondences are under investigation, 
we have commonly to deal with some intermediate degree of corre- 
lation, and r assumes, therefore, the form of a decimal lying 
between and 1.00 for positive and between and — 1.00 for 
negative correspondence.^ 

2. The Computation of the Index of Correlation 

(a) The ' Product-Moments ' Method of Pearson 

The most elaborate as well as the theoretically best possible 
method of computing r is the standard 'product- moments' 
method elaborated by Bravais, Galton, and especially by Pearson. 

In referring to the product-moments as the best possible method, certain 
quaUfications must be kept in mind. It is possible, for instance, that, as 
Spearman contends (17), the comparison of ranks (ig-method), for reasons 
that will be explained later, may be more reliable and satisfactory when 
psychological data are under treatment. 

In any case it is to be remembered that the product-moments method 
applies primarily to the relation of those arrays whose distribution is 'normal' — 
in the sense already explained. The mathematics of correlation for skewed, 
multimodal and other complex forms of distribution have received attention, 
especially at the hands of European mathematicians, but it cannot be said that 
their results have as yet reached a stage where they are of practical usefulness 
to those who have to take their measurement-methods at second-hand. (Cf. 
also Krueger and Spearman, pp. 53-4.) 

Again, it is also possible that functional relations may exist of so simple a 
form as to be readily expressed either verbally or mathematically, which, 
nevertheless, will give a zero coefficient by the standard method. Take, for 
instance, the hypothetical relation that Spearman has adduced as an example 
of zero correlation. Suppose five persons are tested for vision and hearing 
with the following results ( in terms of feet that the test-type is read and the 
sound heard): 

Person A B C D E 



Vision, in feet 6 7 9 11 14 

Hearing, in feet 



A 


B 


C 


D 


6 


7 


9 


11 


6 


11 


12 


10 



^ On the meaning of r, especially in procedure by the method of rank-com- 
parison, see the discussion between Diirr and Spearman (5; 18). 



30 THE TREATMENT OF MEASURES 

Here, says Spearman (15, p. 77), "we get r = 0, and thus there is no corre- 
lation, direct or inverse." But, as Lehmann and Pedersen (9, pp. 16,17) 
have cleverly shown, if these values are plotted graphically, there is revealed 
a simple functional relation, viz: hearing is poor when sight is poor, reaches 
a maximum when sight is fairly good, and then declines when sight continues 
to improve. From this it may be seen that it is best to plot relations in 
graphic form whenever possible. In many cases, indeed, such a functional 
graph is more significant than any coefficient could possibly be, just as a 
curve of distribution is more significant than an M, even when coupled with 
its measure of deviation. 



By the product-moments method 



X r = ^^^, (23) 

\ n 0^02 

in which the x's are the series of deviations from M in the first 
array and the y's the corresponding series of deviations in the 
second array, and in which a^ is the standard de\'iation of the first 
and (72 the standard deviation of the second array, and n the 
number of cases in either array. 

The various steps of the computation may be illustrated by 
reference to Table V for grip of right and left hands, as follows: 

(1) Arrange the original measurements in order of their standing 
or rank, as shown in Columns 1, 3, and 7. (While this is not 
absolutely necessary, it commonly facilitates computation, though 
for speedier determination of the xy values, it might be preferable 
to place the two arrays in the same order by individuals, e. g., as 
shown by the numbers in Columns 2 and 6.) 

(2) Compute M (or the median) for each series (283 and 273). 

(3) Compute and record the individual deviations (d, columns 
4 and 8) for each series, retaining the algebraic signs. 

(4) Multiply the d of each individual in the first series (now 
termed his x) by the d for the same individual in the second array 
(now termed his y), and record the products, observing the algebraic 
signs (the xy values in Column 13), e. g., boy No. 30 has for his 
X,— 125 and for his y, — 135, hence, for his xy, — 125 X — 135 = 
16740. Again, boy No. 25 has for his corresponding values, — 21 
and + 35, hence for xy, — 735. 

' For a fuller illustration of correlation arithmetic, together with suggestions 
for shortening the work, see E. Davenport, pp. 455-471. 



THE PEARSON METHOD 31 

(5) Add the products obtained in (4) (277,371, Column 13). 

(6) Compute the S. D. of both series {o^ and a, in Formula 23, 
illustrated in the d^ columns, 5th and 9th, and explained in Formula 
5): multiply them together, and multiply their product by the 
number of cases (75.8 X 79 X 50 = 299,410). 

(7) Divide the 5th by the 6th resultant for the index desired 
(r = 277,371 ^ 299,410 = + 0.93). 

The arithmetic of the Pearson method is thus simple, though somewhat 
tedious. The work may be materially lessened by the use of Barlow's Tables 
of Squares, Cubes, Square Roots, etc. New York, 1904, of Crelle's Rechentafeln 
(procurable through G. E. Stechert & Co., New York) , which show at a glance 
the products of all numbers up to 1000 X 1000, and by the use of an adding 
machine.* Another considerable shortening may often be effected without 
serious disturbance by substituting Formula 7 for Formula .5 in computing 
the two S. D.'s. Thus, in our illustration, this substitution (see Table .3) gives 
for the denominator of the fraction: 76.9 X 79.3 X 50 = .304,908.50, from 
which we find r = 0.91. 

The probable error of the coefficient of correlation as obtained by 
the Pearson method is calculated by the formula 

P.E.r = 0.6745 ^^^, (24) 

although some mathematicians prefer the formula 

P.^., = 0.6745 ^i^!^- ■ (25) 

Vnd + r^) 

It is evident that the reliability of a coefficient increases with the 
number of cases compared and also with the magnitude of the 
r obtained. The actual values of P. E.^, as computed by Formula 
24 for eleven values of r from to 1 accompanying values of n 
from 25 to 1000, are indicated in Table 5, so that one can not only 
read at a glance the P. E. for a given value of r and n, but also 

' The author has found the Gem adding machine (price $15, procurable 
through the Automatic Adding Machine Co., New York City, or through the 
C. H. Stoelting Co., Chicago) serviceable for work in which there is no neces- 
sity for printed records such as the Burroughs, Standard, Wales, and other 
high-priced machines afford. 



32 



THE TREATMENT OF MEASURES 



determine the value of n, i. e., the number of observations, needed 
to estabhsh a given degree of correlation with any assigned degree 
of accuracy. In our illustrative case, since ?i = 50, and r = .93, 
we note that P. E.^ is less than 0.0181, that 200 observations 
would have reduced the error to less than .0091, etc. If our cor- 
relation had been lower, say 0.30, the error for 50 cases would have 
risen to 0.0868. Since the actual error is extremely small in rela- 
tion to the obtained correlation, it follows that the latter has an 
enormous degree of reliability. 



TABLE 5 
Prohahle Error of r for Various Values of r and of n {Yule) 



VALUES 

OFn 


r = 


r= .1 


r= .2 


r = .3 


r= .4 


r = .5 


r = .6 


r = .7 


r = .8 


r= .9 


r = 1 


25 


.1349 


.1335 


.1295 


.1228 


.1133 


.1012 


.0863 


.0688 


.0486 


.0256 


.0000 


50 


.0954 


.0944 


.0916 


.0868 


.0801 


.0715 


.0610 


.0486 


.0343 


.0181 


0000 


75 


.0779 


.0771 


.0748 


.0709 


.0654 


. 0584 


.0498 


.0397 


.0280 


.0148 


.0000 


100 


.0674 


.0668 


.0648 


.0614 


.0567 


.0506 


.0432 


.0344 


.0243 


.0128 


.0000 


200 


.0478 


.0473 


.0459 


.0435 


.0402 


.0.359 


.0306 


.0244 


.0172 


.0091 


.0000 


300 


. 0389 


.0386 


.0374 


.0354 


.0327 


.0292 


.0249 


.0199 


.0140 


.0074 


.0000 


400 


.0337 


.0334 


.0324 


.0307 


.0283 


.0253 


.0216 


.0172 


.0121 


.0064 


.0000 


500 


.0302 


.0299 


.0290 


.0274 


.0253 


.0226 


. 0193 


.0154 


.0109 


.0057 


0000 


600 


. 0275 


.0273 


.0264 


.0251 


.0231 


.0207 


.0176 


.0140 


.0099 


.0052 


.0000 


700 


.0255 


.0252 


.0245 


.0232 


.0214 


.0191 


.0163 


.0130 


.0092 


.0048 


.0000 


800 


.0238 


.0236 


.0229 


.0217 


.0200 


.0179 


.0153 


.0122 


.0086 


.0045 


.0000 


900 


.0225 


.0223 


.0216 


.0205 


.0189 


.0169 


.0144 


.0115 


.0081 


.0043 


.0000 


1000 


.0213 


.0211 


.0205 


.0194 


.0179 


.0160 


.0137 


.0109 


.0077 


.0041 


.0000 



In general, a correlation, like any other determination, to have 
claim to scientific attention must be at least twice as large as 
its P. E., and to be perfectly satisfactory, should be perhaps three 
to five times as large. 

Since, in our illustration, r is some 51 times as large as its P. E. 
its appearance by mere chance is practically zero and its reliability 
is practically absolute. 

(b) The Pearson Method Adapted to Rank-Differences 

The product-moments method gives full and exact weight to 
the d of each m from the M. If we disregard the magnitude of 



THE METHOD OF RANK-DIFFERENCES 33 

these d's, however, and regard only the relative order or station 
of individual w's in each array, we may yet measure correlation 
by what is known as the method of rank-differences. 
For this method, the formula is 

r = 1 - ^^ , (26) 

c 

in which D is the numerical difference between each corresponding 
pair of ranks^ (not to be confused with d, the deviation from the 
mean), and in which c is the mean value of ^ D^ by mere chance. 
Since 

c = "<"''" , (27) 

6 

Formula 26 may be written: 

r = l- ^-^ . (28) 

n (n' - 1) 

For illustration, note in Table 1, Column 11, the series of 
D's which are squared and summated in Column 12. Boy No. 
30 ranks first (weakest) in the distribution for right-hand grip 
and first in the order for left-hand grip, hence his D = 0. Boy 
No. 522 ig 3(j in the first, and 9th in the second array, hence for 
him D = Q and D^ = 36. Since n = 50, by Formula 27, 

50 (2500- 1)= 20,791; 
'= 6 

hence, by Formula 26, 

,.1_ 209^.1-10=.90, 
20,791 

1 In this and the following rank method of Spearman, cases of 'ties' for a 
given rank are preferably divided in such a manner as to keep the total number 
of ranks equal in the two series. If, for instance, two S's rank 5th, they 
should both be assigned the rank 5.5 (to replace 5 and 6), or if three S's rank 
5th, they should all three be assigned the rank 6 (to replace the 5th, 6th and 
7th places in the series). 

- To avoid possible confusion, it may be explained that two r ecords were 
discarded, so that the boys' numbers run two over the fifty. 



34 THE TREATMENT OF MEASURES 

a result in close accordance with that of the product-moments 
method and obtained in a small fraction of the time. 

(c) Spearman's Correlation 'Foot-Rule,' or R-Method. 

Spearman's " ' foot-rule ' for measuring correlation " (17) is another 
and still simpler method of comparison b}^ rank, the essential feat- 
ures of which are the use of D, the numerical difference of station, 
in place of D^, and of only those of the D's that indicate a gain in 
rank (since the losses must equal the gains). 

It is because this simplified method gives less weight to extreme measures 
that Spearman believes it to be actually more reliable for psychological pur- 
poses than the standard Pearson method. The advantages are summarized 
by Spearman (17, p. 104) as follows: "By using it, we obtain a precise quanti- 
tative value, which can be compared with that found by any other correlation 
under any circumstances or between any other things, either by the same or by 
the standard r-method; we free ourselves from various illusions, which are 
otherwise almost irresistible; we get a reliable estimate as to the danger of 
our result being merely an accidental coincidence; and we even learn how to 
plan out our experiments from the outset in a manner properly adapted to 
the object in view." In the opinion of Lehmann and Pedersen, however, 
Spearman's 'footrule' has only slight value, because it can measure and 
express only proportionality and not other uniform relationships of phe- 
nomena, while even when dealing with proportionality, the method may lead 
to totally false results, e.g., with a complete inverse relation, the value secured, 
instead of —1 would be —0.5 with an odd number of cases, and 1 — 1.5 X n- / 
(/i^- 1) with an even number of cases (9, p. 18). 

This method, it is important to note, yields an index, R, that is 
not identical with the Pearson r, though functionally related there- 
to, as is explained below. 

The formula for Spearman's R is 

/? = 1 - -^ , (29) 

c 

in which cj is the numerical gain in rank of an individual in the 
second, as compared with the first series, and in which c is the mean 
value of - g by mere chance. 
Since: 

c = J (30) 



THE SPEARMAN METHOD 35 

we obtain by substitution: 

R^l-l^l^. (31) 

n^ - 1 

For illustration, note in Table 1, Column 10, the series of gains 
(g), which yield ^ g = 106. As n = 50, by Formula 30, c = (2500 

- 1) - 6 = 416.5; 
hence, by Formula 29, 

R=l - ^^A = l-.25 = .75. 
416.5 

To determine whether R has any claim to reliability, one may 
use the rather severe formula:^ 

P.E.,= ^^^h (32) 

V n 

To convert /^-values into r-values we may use the formula: 

r = sin(~^Ry, (33) 

or, for all cases in which R is less than .50, this may be simplified 
with httle loss of accuracy into: 

r=1.5i^. (34) 

For the quick and accurate conversion of R into r, Table 6' 
which is based on Formula 33, may be consulted. 

In the correlation under examination, since /2 = .75, r = .93, 
or precisely the value obtained by the longer Pearson method. 

(d) Correlation by Distribution of Selected Groups 

The following method is sometimes useful as a device for pre- 
liminary survey, but when used, as it often has been, for a final 

' According to Spearman, if we know that a correlation exists and wish 
merely to estimate the accuracy of R, a less rigorous formula may be used. 



36 



THE TREATMENT OF MEASURES 



expression of correlation, it is inferior to the methods already 
described. 

Distribute the data for both series in order as illustrated in 
Table 1, and divide them into four or five groups on the basis 
of equal numbers of cases or of equal amounts of deviation. By 
inspection it is often possible to determine at this juncture whether 
there is sufficient evidence of a correlation to justify further 

TABLE 6 
Conversion of R-Values into r-Values, in Accordance with Formula 33 



R 


r 


R 


r 


R 


r 


R 


r 


R 


»• 


.00 


.00 


.20 


.31 


.40 


.59 


.60 


.81 


.80 


.95 


.01 


.01 


.21 


.32 


.41 


.60 


.61 


.82 


.81 


.96 


.02 


.03 


.22 


.34 


.42 


.61 


.62 


.83 


.82 


.96 


.03 


.05 


.23 


.35 


.43 


.62 


.63 


.84 


.83 


.96 


.Oi 


.06 


.24 


.37 


.44 


.64 


.64 


.84 


.84 


.97 


.05 


.07 


.25 


.38 


.45 


.65 


.65 


.85 


.85 


.97 


.06 


.08 


.26 


.40 


.46 


.66 


.66 


.86 


.86 


.98 


.07 


.11 


.27 


.41 


.47 


.67 


.67 


.87 


.87 


.98 


.08 


.13 


.28 


.43 


.48 


.69 


.68 


.88 


.88 


.98 


.09 


.14 


.29 


.44 


.49 


.70 


.69 


.88 


.89 


.99 


.10 


.16 


.30 


.45 


.50 


.71 


.70 


.89 


.90 


.99 


.11 


.17 


.31 


.47 


.51 


.72 


.71 


.90 


.91 


.99 


.12 


.19 


.32 


.48 


.52 


.73 


.72 


.90 


.92 


.99 


.13 


.20 


.33 


.50 


.53 


.74 


.73 


.91 


.93 


.99 


.14 


.22 


.34 


.51 


.54 


.75 


.74 


.92 


.94 


1.00 


.15 


.23 


.35 


.52 


.55 


.76 


.75 


.93 


.95 


1.00 


.16 


.25 


.36 


.54 


.56 


.77 


.76 


.93 


.96 


1.00 


.17 


.26 


.37 


.55 


.57 


.78 


.77 


.94 


.97 


1.00 


.18 


.28 


.38 


.56 


.58 


.79 


.78 


.94 


.98 


1.00 


.19 


.29 


.39 


.57 


.59 


.80 


.79 


.95 


.99 


1.00 



calculation. For this inspection we may take the cases found 
in the first group of the first series and examine their distribution 
in the groups of the second series. Evidently, in the absence of 
correlation, these cases would be distributed by chance. Thus, 
in Table 1, let the two series be divided into 5 groups of 10 measure- 
ments each. The 10 measurements in the first group for right- 
hand grip would tend, by chance alone, to be distributed 2 in 



THE METHOD OF GROUP COMPARISON 



37 



each of the 5 groups in the second series, but as a matter of fact 
they are massed in or near the first group (8 in the 1st, 2 in the 2d), 
hence there is evidently a high degree of correlation. 

The distribution in the second series of the remaining groups of the first 
series may be similarly tested, though an examination of the first group is 
commonly sufficient. 

If the grouping is made in terms of deviation, the number of measurements 
found in the several groups will usually be unequal; it is then necessary to 
calculate the distribution of the various groups of the first series into those of 
the second. Suppose the two series of Table 1 are each divided into five 70- 
hectogram groups; the right-hand series will subdivide into groups containing 
16, 15, 12, 4 and 3 measurements; the left-hand series into groups con- 
taining 12, 17, 12, 6 and 3 measurements, respectively. Take the 16 cases in 
the first group of the first series; by chance it is clear that 12/50, or 3.84 
of them, would fall in the first group of the 2d series, 17/50, or 5.44 of them 
would fall in the second group, 3.84 in the third, 1.97 in the fourth, and .98 
in the fifth. The actual distribution of the 16 cases into those five groups is 
11, 5, 0, 0, 0, as compared with the chance distribution, 3.S4, 5.44, 3.84, 1.97, 
.98. 

If now we wish not only to explore the distribution of selected 
groups tentatively for the presence of correlation, but also to 
present the evidence of the correlation in compact form, we may, 
as is often done, prepare a table by comparative averages. To 
return again to the correlation of right and left-hand strength 
of grip, we may by this means secure the following tabular state- 
ment of the relations l^etween right-hand and left-hand grip.^ 



TABLE 7 
Correlation of Right and Left-Hand Grip by Group Averages 



(Whipple) 





1st 10 


2d 10 


3d 10 


4th 10 


5th 10 






Average Right Hand Grip 


194.9 
183.7 


229.9 
226.3 


271.5 
269.2 


317.9 
291.5 


402.2 


Average Left Hand Grip 


394.4 







^For examples of this type of correlation, consult Bagley (1), Binet and 
Vaschide (2). Though this method has been frequently used, a little reflec- 
tion will show that it is inferior to the several methods described before, because 
the advantage of weighing the relation of each individual measure is lost by 
lumping them into averages, and because, moreover, no coefficient of correla- 
tion is computed. If the groups were made more numerous and the data 
presented in the form of a graph showing the entire course of the relationship 
the absence of the coefficient might be less serious. 



38 THE TREATMENT OF MEASURES 

The data from such a table may be thrown into graphic form 
very simply: let ordinates represent the values of lh(! one series, 
abscissae the values of the other, so that the one series is plotted as a 
function of the other: if, then, the first series ranges upward for 
values from low to high and the second from left to right for values 
from low to high, a positive correlation will be indicated by a hne 
running in a southwest-northeast direction, inverse correlation by 
a line running in a northwest-southeast direction, and zero cor- 
relation by a vertical or a horizontal line (depending on which 
series is plotted on the ordinates). In proportion as the corre- 
lation is complete the line assumes an oblique position. 

(e) Correlation of Presence and Absence 

Suppose we wish to correlate two traits whose presence or 
absence is ascertainable, but about whose degree of presence 
nothing can be said. Such a correlation can be computed if we 
first determine: 

a =-- number of cases in which both traits are present, 

b = number of cases in which the first trait is present and 

the second absent, 
c = number of cases in which the second trait is present and 

the first absent, 
d =-- number of cases in which both traits are absent. 

On the basis of these values, we may use the simi)le formula of 

Yule: 

ad - he ,orx 

r = - , {60) 

ad + be 
or, better, the following modification: 

. t: Vad -' \'be ,..,.. 

r = sm • (,ob) 

2Vad + Vbc 

If, in this formula, we replace the sine by the cosine of its comple- 
ment, we secure _ 

- Vad - Vbe 



cos 



2 2\'ad + \'be 



CORRELATION OK PRESENCE AND ABSENCE 39 

which we can reduce to 

(37) 



V fee 

r = cos ^^ __7i. 

V ad + '' be 



The probable error, provided ab is not verj^ unequal to cd, may 
be taken as 

1.1 



P.E., 



V 



(38) 



As an example one may take the measure of the tendency of 
white cats to be afflicted with deafness (as cited by E. Davenport 
from Yule). From the data as presented in Table 8, we may 
calculate by Formula 35 that r = .91. 



TAI5LE 8 
Relation ofDeafnesN and WIdte Color in Cats {Yule) 





CATS 


WHITE 


NOT WHITE 


Deaf 




G 


4 


Not Deaf 




14 


976 











Now this same formula can often be used for preliminary explor- 
ation of series in which the degree of presence of a trait is known, 
and which may, therefore, be treated, if desired, by the more 
elaborate methods. For this purpose, assume that all measure- 
ments greater than M (or the median), i. e., all plus cases, signify 
the presence of the trait, and all minus cases its absence. In Table 
1 we find, using the median, 22 cases that are plus in both series, 
3 that are plus in right and minus in left-hand grip, 3 that are 
minus in right and plus in left-hand grip, and 22 that are minus in 
both. Substituting these values in Formula 37, we have 



Vq 



r =- COS 



-, or COS 21 6° = .93, 



\/ 484 + \/ 9 
which gives again the same value as by the standard formula 



40 



THE TREATMENT OP MEASURES 



(f) The Method of Unhke Signs 

Even this procedure may be simphfied by substituting for ybc 
the percentage of cases with unhke signs (U), and for 1^ ad the per- 
centage of cases with hke signs (Ly with the result, 

u 



COS 



L+ [7 



or, since L + U must always equal 100, and since tt = 180° 
formula may be condensed, if desired, to 

r^ cos U 1.8°. 



(39) 



this 



(40) 



Finally, since U must lie between 50 and for positive and 
between 50 and 100 for inverse correlations, a talkie may be pre- 
pared- from which the values of r may be read directly from any 
integer value of U. 

By reference to the paragraph above it will be seen that in Table 
1 we have 6 cases of unlike signs in the 50, hence U = 12 and r = 
0.93, as by other methods. 



TABLE 9 

Corresponding Values of r and U for Formula J^O (Whipple) 
If U is greater than 50, first subtract it from 100, then prefix the mimis sign 
to the correlation indicated 



u 


r 


u 


r 


u 


r 


U 


r 


U 


r 





1.000 


10 


.951 


20 


.809 


30 


.587 


40 


.309 


1 


.999 


11 


.941 


21 


.790 


31 


.562 


41 


.279 


2 


.998 


12 


.929 


22 


.770 


32 


.536 


42 


.248 


3 


.995 


13 


.917 


23 


.750 


33 


.509 


43 


.218 


4 


.992 


14 


.904 


24 


.728 


34 


.482 


44 


.187 


5 


.987 


15 


.891 


25 


.707 


35 


.454 


45 


.156 


6 


.982 


16 


.876 


26 


.684 


36 


.426 


46 


.125 


7 


.976 


17 


.860 


27 


.661 


37 


.397 


47 


.094 


8 


.968 


18 


.844 


28 


.637 


38 


.368 


48 


.062 


9 


.960 


19 


.827 


29 


.613 


39 


.338 


49 


.031 



' That is , virtually substituting the arithmetical for the geometrical mean. 
^ Reproduced from an earlier article by the author (23) in which the applic- 
ability of the method is discussed more fully. 



CORRECTION OF CORRELATIONS 41 

This method cannot be recommended for final determinations 
of important correlations because the probable error is too large, 
but it is a useful device for quick examination of a relation. 

The m?thod of unlike signs, in sharp contrast to the product-moments 
method, disregards entirely the amount of deviation. The author has made 
occasional use, for the first approximation, of an intermediate method that 
also disregards the actual deviations, but introduces artificial ones to be 
treated by the standard Pearson formula. Assume that all measurements 
lying between M (or the median) and the A. D. (or S. D., or P. E.) have a 
deviation of 1 (plus or minus according to direction of the actual deviations), 
and that all other measurements have a deviation of 2 (plus or minus). Com- 
pute Ixy, (7, and o^ precisely as if these assumed deviations were the actual 
ones. This method, when applied to Table 1, yielded r = .97 when a was 
calculated by Formula 7, and r = .87 when a was calculated by Formula 5. 

3. The Correction of Obtained Correlations to their True Value 
(a) Correction of the Attenuation Produced by Chance Errors 

The real correspondence between two traits or capacities is 
not, as has so often been erroneously supposed, necessarily revealed 
by the determination of a coefficient of correlation, even by the 
most approved methods and with a probable error that is satis- 
factorily small. All measurements, as we have noted, are subject 
to chance errors of observation. In the determination of averages 
such errors tend to counterbalance one another, so that if the 
measurements are sufficiently numerous, the obtained M differs 
from the true M by an inappreciable amount. In the case of 
correlations, however, these errors^ are not eliminated by increas- 
ing the number of observations, and their presence has the effect 
of decreasing the size of the correlation, so that, in so far as these 
errors are concerned, the ' raw' or obtained correlation is too small, 
or, to use Spearman's term, the correlation is 'attenuated' by 
errors which constitute, from this point of view, constant or sys- 
tematic errors. 

^ The phrase 'errors of observation' i s to be understood in a wide sense, to 
include not only errors arising from technique, instrumentation, etc., but also 
chance shifts in the disposition of subjects, in their attitude toward the test, 
etc. 



42 THE TREATMENT OF MEASURES 

This illusory attenuation of the correlation by errors of observation seems, 
in fact, a principal cause of the contradictory nature of results that have 
hitherto been obtained ; in experiments in which such errors have been very large, 
a correlation has not appeared, even when present, and has, in consequence, 
been erroneously denied. The determination of a small correlation therefore 
opens two possibihties ; it may indicate actual absence of correspondence, or 
it may indicate merely the presence of large chance errors of observation. 
(Kriiger and Spearman, p. 55.) 

In order to correct the raw and discover the true r, it is impera- 
tive to secure at least two independent series of observations. 
The formula for correction of attenuation, or the 'expanding' 
formula, as it might be termed, is then applied as follows: 

.„ _ ikf (A,B;, A,B„ A,B„ A3.j ,,,, 

^^' m(a,a,b;b;)"""^" '*^' 

in which 

AB^ = the true correlation, 
M = the mean, 

A, = the 1st series of observations of the trait A, 
A.J = the 2d series of observations of the trait A, 

B, = the 1st series of observations of the trait B, 
B, = the 2d series of observations of the trait B, 

A,Bi =^ the raw correlation of Aj and B,, 
AjA, = the raw correlation of Aj and A,., etc. 

Thus the numerator is the M of the four possible r's between the measure- 
ments of A and the measurements of B, while the denominator is the M of 
the r of the two A series and the r of the two B series. Incidentally, these 
last mentioned correlations, taken singly, afford an obvious coefficient of 
reliabihty of the two series of measurements of A and B respectively. 

The above formula holds for ordinary cases, but if one series of observations, 
say A, should be known to be much more exact and reliable than the other, 
then the geometrical should be substituted for the arithmetical M. In theory 
the denominator should always be the geometrical M, but the arithmetical 
M is virtually as accurate and for short series even more desirable. For the 
mathematical demonstration of this and the following formulas, the accuracy 
of which has been disputed by several writers, consult Spearman (15). The 
correction does not entirely eliminate the uncertainty that arises from the 
use of 'random samples' for investigation; that must be removed by the use 
of more extended series. 



CORRECTION OF CORRELATIONS 43 

(b) Correction of the. 'Constriction' or 'Dilation' Produced by 
Constant Errors 

Attenuation is the result of the operation of chance errors, — 
chance in the sense that the deviation of any measurement takes 
place independently of the deviation of any other measurement. 
If, however, some influence is at work which affects all the measure- 
ments of one or of both series, such a constant factor or con- 
stant error will prove a source of disturbance that may either 
increase or decrease the obtained correlation. Such disturbances 
will result from the operation of any factor which is not strictly 
relevant to the correspondence under examination. 

If an irrelevant factor affects both of the series, it is evident 
that the correlation will be unduly increased or ' dilated. ' Suppose 
for example, that one wished to determine the correlation of 
pitch discrimination with the discrimination of lifted weights, 
and that the subjects of the exj^eriments wert of different ages. 
Then, since the two capacities in question both tend to improve 
with age, this common dependence on age will clearly tend to 
induce the appearance of a correlation, even if there really be 
none between the capacities themselves when compared under 
uniform conditions of age.^ 

If an irrelevant factor affects but one of the series, it is evident 
that the correlation will be unduly decreased or 'constricted,' 
i. e., the irrelevant influence will tend to reduce any proportionality 
that really exists between the two series. To quote an example 
from Spearman, a correlation of 0.49 was discovered between 
pitch discrimination and school standing, but it was likewise 
discovered that more than half the children had 'taken lessons,' 
and thus had the opportunity for special training in the obser- 
vation of pitches. 

These constant irrelevant factors may not always be excluded? 

^ This undiscovered or neglected influence of age has been a very common 
source of error in many studies of correlation. Obviously, this particular 
irrelevancy may be eliminated practicallyby proper selection of subjects for 
the investigation, or it may be eliminated by manipulation of the results 
in various ways besides that here described: see, for example, Bagley. 



44 THE TREATMENT OF MEASURES 

but their force can frequently be measured and allowed for by 
the following formula ;! 

AB, = AB^-AC BC ^2^ 

V a- AC) (1 - BC^) 
in which 

ABj = the true correlation between A and B, 
ABa = the apparent correlation between A and B. 
AC = the direct correlation between A and any irrelevant fac- 
tor, C, 
BC = the direct correlation between B and C. 

If, as is most often the case, the irrelevant factor affects but 
one series, this influence of 'constriction' may be excluded by the 
simpler formula: 

AB, = ^--A^^ (43) 

V a- Ac^) 

Thus, in the example mentioned, the correlation between pitch 
discrimination and its disturbing factor, musical training, was found 
b}^ computation, to be 0.61 ; hence, by Formula 43, 

r= Q-^Q - = 0^9 

V 1 -0.61- 

From the above considerations, it follows that the experimenter must define 
with some exactness the traits that are to be examined for a possible correla- 
tion, and that he must not seek to establish the correlation until, by means of 
suitable preliminary exploration, he has discovered all the irrelevant factors 
that might disturb the correspondence. The mere mechanical computation 
of an index of correlation does not, then, demonstrate the existence of a real 
correlation, or at least, does not accurately and certainly define its nature. 
Hence, while, as we have seen, we may very hopefully look to correlational 
work for revelation of the functional disposition of mind, this is no royal road 
to the attainment of the end, but can itself be entered upon in each instance 
only after a preparatory survey and critical inspection of the problem in hand 
has afforded sufficient acquaintance with the traits and capacities that are 
therein concerned. One must be a psychologist as well as a statistician. ^ 

^ AB, AC and BC must first be 'expanded' by Formula 41. 

^ The study of the functional correlation of five well-known tests by Krviger 
and Spearman affords an admirable illustration of the value of such a comliina- 
tion of sound psychology and sound statistics. 



FACTORS IN INTERCORRELATIONS 45 

4. The Discovery of Common Factors in Inter correlated Capacities 

If three or more psychological traits show intercorrelations 
one with another, the question may be raised as to whether the 
intercorrelations are not due to the presence of some common 
factor to which all the capacities are functionally related, whether, 
in other words, these correlations may not arise from a single 
underlying cause. If such a common or 'central' factor be 
assumed to be present, we may test the validity of the assumption 
by mathematical procedure, leaving the exact nature of the factor 
out of consideration for the time being. For example, if for any 
given capacity. A, we have obtained two independent measure- 
ments, A, and A,, and if for two other capacities, we have obtained 
the measurements B and C respectivelj^, then the correlation (AF) 
between the capacity A and the hypothetical common or central 
factor, F, may be determined by the formula : 

^j,_ JW(AB,BC) ^ > 

^^ m1a7a;;bc) • ^**' 

In illustration, Kriiger and Spearman found the following values, — 
correlation of pitch discrimination with the Ebbinghaus comple- 
tion test, 0.65, with adding, 0.66, correlation of two measurements 
of pitch discrimination, 0.87, correlation of the Ebbinghaus test 
with adding, 0.66; hence the correlation of pitch discrimination 
with the hypothetical central factor is the M of 0.65 and 0.66 
divided by the M of 0.87 and 0.71, or 0.83.i 

REFERENCES ^ 

(1) W. C. Bagley, On the correlation of mental and motor ability in school 
children, in A. J. P., 12: 1901, 193-205. 

(2) A. Binet and N^. Vaschide, Experiences de force musculaire et de fond 
ohez les jeunes gargons in A. P., 4: 1897 (1898), 15-63. 

^ This central factor is tentatively ascribed by these authors to some 
psychophysiological condition, possibly general neural plasticity. In another 
article Spearman speaks of "General Discrimination" or "General Intelli- 
gence," or the "Intellectual Function." Here, again, is revealed the instruc- 
tive wealth of possibilities in the application of adequate methodological 
treatment to psychic life. 

^ Consult the List of Abbreviations for the exact titles of periodicals in these 
and subsequent references. 



46 THE TREATMENT OF MEASURES 

(3) C. B. Davenport, Statistical methods, with special reference to biologi- 
cal variation, N. Y., 1899. Pp. 148. (2d revised edition, 1904.) 

(4) E. Davenport, Principles of breeding; a treatise on thremmatology, 
Boston, 1907. Pp. 713. (With an appendix on statistical methods by H. 
Rietz.) 

(5) E. Durr, review of Spearman (15, 16), in Z. P., 41: 1906, 450. Also, 
Erwiderung, in Z. P., 42: 1906, 470-2. 

(6) W. P. Elderton, Frequency curves and correlation, London. 1906. 

(7) F. Galton, Natural inheritance, London, 1889. Pp. 259. 

(8) F. Krueger and C. Spearman, Die Korrelation zwischen verschiedenen 
geistigen Leistungsfiihigkeiten, in Z. P., 44: 1907, 50-114. 

(9) A. Lehmann and R. Pedersen, Das Wetter und unsere Arbeit, in A. G. 
P., 10: 1907, 1-104, especially 15-26. 

(10) M. Merriman, A text-book on the method of least squares, N. Y., 
1884. Pp. 194. 

(11) M. Meyer, The grading of students, in Science, 28: 1908, 243-250. 

(12) H. Rietz: see E. Davenport. 

(13) E. C. Sanford, A course in experimental psychology, Boston, 1895 
and 1898. Pp. 449. 

(14) E. W. Scripture, The new psychology, London, 1897. Pp. 500. 

(15) C. Spearman, The proof and measurement of association between two 
things, in A. J. P., 15: 1904, 72-101. 

(16) C. Spearman, General intelligence objectively determined and meas- 
ured, in A. J. P., 15: 1904, 201-293. 

(17) C. Spearman, 'Footrule' for measuring correlation, in B. J. P., 2: 
1906, 89-109. 

(18) C. Spearman, Entgegnung, in Z. P., 42: 1906, 467-470. 

(19) C. Spearman, Demonstration of formulae for true measurements of 
correlation, in A. J. P., 18: 1907, 161-9. 

(20) E. L. Thorndike, Educational psychology, N. Y., 1903. Pp. 173. 

(21) E. L. Thorndike, An introduction to the theory of mental and social 
measurements, N. Y., 1904. Pp. 210. 

(22) E. B. Titchener, Experimental psychology, vol. ii. Quantitative 
experiments. Parts 1 and IT, N. Y., 1905. 

(23) G. M. Whipple, A quick method for determining the index of corre- 
lation, in A. J. P., 18: 1907, 322-5. 

(24) C. Wissler, The correlation of mental and physical tests, in P. R. M. S., 
3: No. 6, 1901. Pp. 62. 



THE TESTS 

CHAPTER IV 

Anthropometric Tests 

The tests embraced in this chapter have been developed pri- 
marily as anthropometric tests. They do not include tests of 
physical capacity or function (Chapter V), but simply measure- 
ments of bodily size or dimension. 

The number of such measurements that have been made and 
recorded runs well into the hundreds, and an extensive literature 
has appeared. The science of anthropometry has developed 
partly in connection with anthropology and sociology, partly in 
connection with the study of physical development, including 
bodily growth, hygiene, gymnastic and athletic training. In 
recent years, moreover, a not inconsiderable contribution has been 
made by psychologists, physicians, educators, and other investi- 
gators who have been interested in the correlation between bodily 
and mental traits. 

It is this last-mentioned phase of anthropometry that concerns 
us, and hence only a few important measurements that have 
assumed special importance in conjunction with other physical 
and with mental tests are here considered. 

The references which follow will enable the reader to study 
the development of anthropometry and the application of anthro- 
pometric tests at large. Bertillon and Galton should be con- 
sulted by those who are interested in the use of anthropometric 
measurements in the identification of criminals: Key and Hertel 
have given special consideration to the relation of growth to disease 
and to hygienic conditions. Anthropometric charts or record- 
books have been published by E. Hitchcock. D. A. Sargent, 
J. W. Seaver, W. W. Hastings, Anna Wood, L. H. Guhck, and 
others. 



48 ANTHROPOMETRIC TESTS 

REFERENCES 

(1) A. Bertillon, Signaletic instructions; including the theory and practise 
of anthropometrical identification, Eng. Trans., Chicago and New York, 1896. 
Pp. 260 + 81 plates, charts, etc. 

(2) H. G. Beyer, The growth of United States naval cadets, in Proc. U. 
S. N. Inst., 21: No. 2, 1895. 

(3) F. Boas, The correlation of anatomical or physiological measurements, 
in Amer. Anthropologist, 4: 1894, 313. 

(4) F. Boas, The growth of children, in Science, 19: 1892, 250. 

(5) F. Boas, On Dr. W. T. Porter's investigation of the growth of the school 
children of St. Louis, in Science, 1: 1895, 225. 

' (6) F. Boas, Growth of first-born children, in Science, 1: 1895, 402. 

(7) F. Boas, Growth of Toronto children, in Rept. Brit. Ass. Adv. Science 
for 1897, 1898, 443. 

(8) F. Boas, Growth of American children, in U. S., 1896-7, ii, 1555. 

(9) H. P. Bowditch, The growth of children, in 10th An. Rept. State Brd. 
Health, Mass., 1879, 33. 

(10) H. P. Bowditch, The growth of children, studied by Gallon's method 
of percentile grades, in 22d An. Rept. State Brd. Health, Mass., 1891, 479. 

(11) F. Burk, Growth of children in height and weight, in A. J. P., 9: 
1897-8, 253. 

(12) A. Engelsperger and O. Ziegler, Beitrage zur Kenntnis der physischen 
und psychischen Natur des sechsjahrigen in die Schule eintretenden Kindes. 
Anthropometrisches Teil, in E. P., 1: 1905, 173-235. 

(13) Lucy Ernst and E. Meumann, Das Schulkind in seiner korperlichen 
und geistigen Entwicklung. Part 1, by L. Ernst, Leipzig, 1906. Pp. 143. 

(14) W. Farr, et al., Table showing the relative statures of boys at the age 
of 11 to 12 years under different social and physical conditions of Hfe, in Rept. 
Brit. Ass. Adv. Science, 1880, i, 127. 

(15) F. Galton, Proposal to apply for anthropological statistics from 
schools, in J. Anthrop. Inst., 3: 1873-4, 308. 

(16) F. Galton, On the height and weight of boys aged 14 in town and 
country schools, in Nature, 5: 1875-6, 174. 

(17) F. Galton, Range in height of males at each age and in several classes, 
in Rept. Brit. Ass. Adv. Science, 51 : 1882, 250. 

(18) F. Galton, Head growth in students at the University of Cambridge, 
in Nature, 38: 1888-9, 14. 

(19) F. Galton, Useful anthropometry, in Proc. Amer. Ass. Adv. Phys. 
Educ, 6: 1891, 51. 

(20) F. Gallon, Anthropometrical instruments, in Anthrop. J., 16: 2. 

(21) F. Galton, Anthropometric percentiles, in Nature, 31: 1884-5,223. 

(22) F. Galton, Finger-prints, London, 1892. Pp. 216. 

(23) A. Gihon, Physical measurements, in Wood's Ref. Haiid-bk. Med. 
Sciences, 5: 1887, 667. 



ANTHROPOMETRIC TESTS 49 

(24) N. -A. Gratsianoff, Data for the study of physical development in 
childhood ( in Russian), St. Petersburg, 1889. 

(25) J. M. Greenwood, Heights and weights of children, in PubHc Health 
Ass. Kept., 1891, Concord, N. H., 17: 1892, 199. 

(26) E. Hartwell, Anthropometry in the United States, in Amer. Statis. 
Ass., 3: 554. 

(27) E. Hartwell, Rept. of the director of physical training, Boston Normal 
Schools, in School Doc, No. 8, Boston, 1894. 

(28) E. Hartwell, Rept. of the director of physical training, in School Doc, 
No. 4, Boston, 1895. 

(29) E. Hartwell, Bowditch's law of growth and what it teaches, reprint 
from 10th An. Proc Amer. Ass. Adv. Phys. Educ, Concord, N. H., 1896. 

(30) W. Hastings, A manual for physical measurements for use in normal 
schools, public and preparatory schools, etc., Springfield, Mass., 1902. Pp. 
112. 

(31) A. Hertel, Neuere Untersuchungen uber den allgemeinen Gesund- 
heits-Zustand der Schiller u. Schiilerinen, in Schulgesundheitspflege, Nos. 
6 and 7, 1888, 167-183, 201-215. (Contains a review of the work of Key.) 

(32) E. Hitchcock, Jr., Physical measurements, fallacies, and errors, in 
Proc. Amer. Ass. Adv. Phys. Educ, 1887, 35. 

(33) E. Hitchcock, Jr., A synoptic exhibit of 15,000 physical examinations, 
Ithaca, 1890. 

(34) E. Hitchcock, Comparative study of measurements of male and 
female students at Amherst, Mt. Holyoke, and Wellesley Colleges, in Proc. 
Amer. Ass. Adv. Phys. Educ, 6: 1891, 37. 

(35) E. Hitchcock, The results of anthropometry as derived from the 
measurements of the students of Amherst College, Amherst, 1892. 

(36) E. Hitchcock and H. Seelye, An anthropometric manual, giving the 
average and mean physical measurements and tests of male college students, 
and modes of securing them, Amherst, 1889. 

(37) B. Holmes, A study of child growth, being a review of the work of 
Dr. Wm. T. Porter, of St. Louis, in N. Y., Med. J; 60: 1894, 417. 

(38) W. Jackson, Jr., Graphic methods in anthropometry, in Phys. Educ, 
2: 1893, 89. 

(39) A. Key, Schulhygienische Untersuchungen, trans, and edited, some- 
what condensed, from the Swedish, by L. Burgerstein, Hamburg and Leipzig, 
1899. (Report of the Swedish Commission of 1882 to investigate hygienic 
conditions of the schools.) 

(40) A. MacDonald, Experimental study of children, including anthro- 
pometrical and psychophysical measurements of Washington school children, 
reprint of chs. 21 and 25 of U. S., 1897-8, Washington, 1899. 

(41) P. Malling-Hansen, Perioden im Gewicht der Kinder und in der 
Sonnenwarme, Copenhagen, 1886. 

(42) S. Moon, Measurements of the boys of the McDonogh School, 
McDonogh, Md., 1893. 



50 ANTHROPOMETRIC TESTS 

(43) K. Pearson, Growth of St. Louis children, in Nature, 51: 1894, 145-6' 

(44) G. Peckhara, The growth ©f children, in Kept. Wis. Brd. Health, 1881, 
28. 

(45) (i. Peckham, Various observations on growth, ibid., 1882, 185. 

, (46) W. T. Porter, On the application to individual school children of the 
mean values derived from anthropological measurements by the generahzing 
method, in Pub. Amer. Statis. Ass., n. s. 3: 1892-3, 576. 
,, (47) W. T. Porter, The growth of St. Louis children, in Trans. Acad. 
Science, St. Louis, 6: 1894, 263. 

(48) W. T. Porter, Physical basis of precocity and dullness, ibicJ., 6: 1893-4, 
160. 

- (49) W. T. Porter, The relation between growth of children and their 
deviation from the physical type of their sex and age, ibid., 233. 

(50) W. T. Porter, Use of anthropometrical measurements in schools, in 
Educ. Rev., 11: 1896, 126-133. 

(51) C. Roberts, A manual of anthropometry. 

(52) Sack, Physical development of the children in the middle schools of 
Moscow, 1892. 

(53) D. Sargent, Report on anthropometric measurements in Proc. Amcr. 
Ass. Adv. Phys.'Educ, 2: 1886, 6. 

(54) D. Sargent, Anthropometric apparatus, with directions for measur- 
ing and testing the principal physical characteristics of the human body, 
Cambridge, Mass., 1887. 

' (55) D. Sargent, The physical proportions of the typical man. in Scrihner's 
Magazine, 2: 1887, 3. 
■-(55) D. Sargent, The physical development of women, ibid., 5: 1889, 541. 

(56) D. Sargent, Strength-tests and strong men at Harvard, in J. Boston 
Soc. Med. Sci., No. 13, 1896-7. 

(57) G. Schultz, Some new anthropometrical data, in Yale Med. J., 2: 
1895-6, 149. 

(58) J. Seaver, Anthropometry and physical examination. New Haven, 
1890. 

(59) G. Sergi, An anthropological cabinet for pedagogic purposes, in 
Education, 7: 1886, 42-9. 

(60) C. Stratz, Der Korper des Kindes, fur Eltern, Erzieher, Aerzte. u. 
Kunstler, Stuttgart, 1904. 

(61) F. Swain, Anthropometric measurements, in Proc. .-Vmer. Ass. Adv. 
Phys. Educ, 3: 1887, 43. 

(62) G. Tarbell, On the height, weight, and relative growth of normal and 
feeble-minded children, in Proc. 6th An. Session Ass. Med. Officers Amer. Inst. 
Idiotic and Feeble Minded Persons, Phil., 1883, 188. 

(63) R. Thoma, Untersuchungen iibcr die Grosse u. das Gewichtder ana- 
tomischen Bestandtheile des menschlichen Korpers, 1882.. 

(64) E. B. Titchener, Anthropometry and experimental psychology, in 
Philos. Review, 2: 1893, 187-192. 



TEST 1: HEIGHT 51 

(65) F. Tackermann, Anthropometric data based upon nearly 3,000 meas- 
urements taken from students, Amherst, 18SS. 

(66) G. West, Worcester school children; the growth of the body, head, and 
face, in Science, 21: 1893, 2-4. 

(67) G. West, Observations on the relation of physical development 
to intellectual ability, made on the school children of Toronto, Canada, in 
Science, n. s. 4: 1896, 156. 

(68) C. Wissler, Growth of boys; correlations for the annual increments, 
in Amer. Anthropol., n. s. 5: 1903, 81. 

(69) M. Wood, Anthropometric tables, arranged after the method of per- 
centile grades, of the measurements of 1500 Wellesley students. 

(70) M. Wood, Anthroporrietric tables, compiled from the measurements 
of 1100 Wellesley College students, 1890. 

(71) M. Wood, Statistical tables concerning the class of 1891 of Wellesley 
College, numbering 104 women. 

(72) M. Wood, Statistical tables, showing certain measurements of forty 
freshmen of Wellesley College (before and after gymnasium training), 1892. 

TEST I, 

Height, standing and sitting. — The general purpose of this test 
is, of course, to furnish a measurement of height as an index of 
physical size or growth for the sake of comparison with mental 
traits or with other physical traits. It is included in practi- 
cally every series of tests that include any physical measurements. 

Apparatus. — Stadiometer (Fig. 3). Small calipers (Fig. 4) or 
miUimeter rule. 

Method. — (1) For standing height, the examiner, E, should, 
when feasible, have the subject, S, remove his shoes, and stand on 
the stadiometer with the heels together and with heels, buttocks, 
the spine between the shoulders, and the head, all in contact 
with the measuring rod. The chin must not be unduly raised or 
depressed. E then brings down the sliding arm of the instrument 
until it rests squarely, but without excessive pressure, upon S's 
head. 

(2) For sitting height, let S sit erect upon the stand of the stadi- 
ometer with spine and head in contact with the measuring rod. 

Results. — (1) The best norms of stature are doubtless those 
calculated bj^ Boas (3)^ from studies by various investigators 

' The figures in parentheses following names refer to the reference- 
numbers at the end of the test in which they occur. 



52 



ANTHROPOMETRIC TESTS 



of school children (45,151 boys and 43,298 girls) in Boston, St. 
Louis, Milwaukee, Toronto, and Oakland, Cal.i For the sake 
of comparison with these norms and with the norms for strength 




FIG. 3. STADIOMETER, OR HEIGHT STAND. 

Graduated in tenths of inches on one side and millimeters on the other. 




FIG. 4. VERNIER CALIPER, FOR EXTERNAL, INTERNAL, AND DEPTH MEASURING. 

Fitted with both English and metric scales and verniers for each, reading 
to lis of an inch and to of a millimeter. 

^ The same averages converted into inches may be found in Burk, while 
these and other studies are summarized by MacDonald. Consult Boas for 
table showing the distribution of stature at each age according to the fre- 
quency method. Valuable tables and charts showing the distribution of height 
and of other anthropometric measurements by percentile grades will be found 
in Smedley (17). 



TEST 1 : HEIGHT 



53 



of grip, vital capacity, etc., to be quoted later, there are given 
herewith the norms of standing and sitting height derived from the 
measurement of 2788 boys and 3471 girls by Director Smedley of 
the Department of Child-Study and Pedagogic Investigation, 
Chicago (16). 

TABLE 10 
Norms of Stature of American Children, in cm. (Boas)* 



Age 


5.5 


6.5 


7.5 


8.5 


9.5 


10.5 


11.5 






Boys 

Girls 


105.90 
104.88 


111.58 
110.08 


116.83 
116.08 


122.04 
121.21 


126.91 
126.14 


131.78 
131.27 


136.20 
136.62 



Age 


12.5 


13.5 


14.5 


15.5 


16.5 


17.5 


18.5 






Boys 

Girls 


140.74 
142.52 


146.00 
148.69 


152.39 
153.50 


159.72 
156.50 


164.90 
158.03 


168.91 
159.14 


171.07 



*The figures in black-faced type in Tables 10-14 indicate periods in which the averages 
for girls exceed those for boys of the same ages. The rapid growth of puberty and early 
adolescence is initiated and terminated earlier in girls than in boys. 



TABLE 11 
Norms of Standing and Sitting Height, in cm. {Smedley) 





STANDING HEIGHT 


SITTING 


HEIGHT 


AGE 


STANDING 


HEIGHT 


SITTING HEIGHT 


AQB 




















BOYS 


GIBLS 


BOYS 


GIRLS 




BOYS 


GIRLS 


BOYS 


GIRLS 


6.0 


110.69 


109.66 


62.40 


61.72 


12.5 


141.89 


144.32 


74.70 


76.29 


6.5 


113.25 


112.51 


63.54 


62.90 


13.0 


145.54 


147.68 


76.24 


77.91 


7.0 


115.82 


115.37 


64.67 


64.07 


13.5 


149.09 


151.04 


77.79 


79.54 


7.5 


118.39 


118. '22 


65.78 


65.25 


14.0 


151.92 


153.64 


79.21 


80.99 


8.0 


120.93 


120.49 


66.75 


66.34 


14.5 


154.74 


156.24 


80.64 


82.43 


8.5 


123.48 


122.75 


67.72 


67.43 


15.0 


158.07 


156.83 


82.18 


83.21 


9.0 


126.14 


125.24 


68.79 


68.32 


15.5 


161.41 


157.42 


83.68 


83.99 


9.5 


128.80 


127.74 


69.85 


69.21 


16.0 


164.03 


158.30 


85.43 


84.54 


10.0 


130.91 


130.07 


70.56 


70.05 


: 16.5 


166.65 


159.18 


87.17 


85.09 


10.5 


133.03 


132.41 


71.26 


70.89 


17.0 


167.85 


159.26 


88.16 


85.20 


11.0 


135.11 


135.35 


72.10 


72.23 


17.5 


169.04 


159.34 


89.14 


85.30 


11.5 


137.19 


138.30 


72.93 


73.58 


18.0 


171.23 


159.42 


90.30 


85.51 


12.0 


139.54 


141.31 


73.80 


74.93 


18.5 


173.41 


159.50 


91.46 


85.72 



54 ANTHROPOMETRIC TESTS 

From these and other statistics, the following important results 
may be gathered : 

(2) There is a period of slower growth in height in boys at 1 1 
years of age, and a similar, though less marked, retardation in 
girls at nine years of age. 

(3) During the period of approximately 11 to 14 years girls 
are taller than boys of the same age, because the prepul^ertal 
acceleration of growth occurs earlier in girls. 

(4) Sitting-height follows the same general laws as standing- 
height. 

(5) Boys continue their growth in height later than do girls, 
i. e., maturity in height is not reached so early. 

(6) Children of purely American descent are taller than those 
of foreign-born parentage (Bowditch, Peckham) . 

(7) Children of the non-laboring classes are as a group taller 
than children of the laboring classes (Bowditch, Roberts). 

(8) According to Bowditch, large children make their most 
rapid growth at an earlier age than small ones, but according to 
Boas (1, 2) this induction is untenable. 

(9) The height of American-born children is modified by den- 
sity of population. Urban life decreases stature from five years 
of age (Peckham, 10, 11). 

(10) According to Kline, boys in the public schools are taller 
than boys in truant schools, save at the age of ten. Similarly, 
Smedley (17) found the boys in the Chicago School for incorrigibles 
and truants shorter than normal boys from the tenth year up. 

(11) Gratsianoff and Sack in Russia, and Porter (39-40), Mac- 
Donald and Smedley (17) in America, have concluded that bright 
children are taller than dull children. West (18), however, found 
exactly the opposite to be true, while Gilbert (6, 7) found no con- 
stant relation between height and mental ability. Porter and 
Smedley determined mental ability by the relation of grade and 
age, Gilbert and MacDonald by the teacher's estimate. 

(12) Children with abnormalities are inferior in height to 
children in general (MacDonald). 

Notes. — The upright measuring rod should be braced m such a 
manner that it will not be bent out of place by the pressure of 
*S's back. Many S's will be inclined to assume an unnatural 



TEST 1 : HEIGHT 55 

position in this examination, especially to stretch themselves: 
the apparent height may be increased by as much as 20 to 30 mm. 
in this way. 

If it is not practicable to remove the shoes, height may be taken 
with, them on, arid the height of the heel may subsequently be 
determined by the use of the small calipers or millimeter rule, 
and then subtracted from the gross height; the resulting error will 
be very small. 

Height, as is well known, decreases slightly during the day, 
owing to the packing of the intervertebral cartilages and the loss 
of muscular tone: this loss in height during the day amounts, 
in the case of young men, to from 10 to 18 mm. It is therefore 
desirable, for accurate work, to take height measurements at 
approximately the same period of the daj^ It might be possible 
to work out empirically a corrective formula. 

Porter's correlation between height and mental ability raises 
an important question which reappears whenever we discuss the 
correlation between any physical trait, e. g., weight, strength, 
vital capacity, etc., and mental abihty. The trend of evidence 
is to the effect that all such correlations, where found, are largely 
explicable as phenomena of growth, i. e., as correlations with 
relative maturity (Cf. Boas, 2; Wissler, 19). This makes intelli- 
gible the fact that, in general, the positiveness of all such correla- 
tions lessens with age, and that many of them, indeed, become 
difficult or impossible of demonstration in adults. Thus, to take 
the correlation in question, a positive correlation is not, of course, 
to be interpreted as meaning that, taken individually, all tall 
boys are, ipso facto, bright boys, but that, taken collectively, 
those boys whose physical condition is good, whose growth is 
unimpaired by ill-health, faulty nutrition, etc., and who reahze 
to the full the possibility of physical development inherent in 
them (whether they will ultimately be short or tall) will be found 
to exhibit the best mental condition and the most rapid mental 
development. 

REFERENCES 

(1) F. Boas, The growth of children, m Science, 19: 1892, 250. 

(2) F. Boas, On Dr. W. T. Porter's investigation of the growth of the 
scliool children of St. Louis, in Science, n. s. 1: 1895, 225. 



56 ANTHROPOMETRIC TESTS 

(3) F. Boas, Growth of American children, in U. S., 1896-7, ii. 1555. 

(4) H. P. Bowditch, The growth of children, studied by Galton's method 
of percentile grades, in 22d An. Rept. State Brcl. Health Mass., 1891, 479. 

(5) F. Burk, Growth of children in height and weight, in A. J. P., 9: 
1897-8, 253. 

(6) J. A. Gilbert, Researches on the mental and physical development of 
school children, in Yale S., 2: 1894, 40-100. 

(7) J. A. Gilbert, Researches upon school children and college students, in 
Iowa S., 1: 1897, 1-39. 

(8) L. W. Kline, Truancy as related to the migratory instinct, in Pd. S. 
5: 1898, 381-420. 

(9) A. MacDonald, Experimental study of school children, etc., in U. S., 
1899 (chs. 21 and 25.). 

(10) G, Peckham, The growth of children, in Rept. Wis. Brd. Health, 
1881, 28. 

(11) G. Peckham, Various observation on growth, ibid., 1882, 185. 

(12) W. T. Porter, The growth of St. Louis children, in Trans. Acad. 
Science, St. Louis, 6: 1894, 2(53. 

(13) W. T. Porter, Physical basis of precocity and dullness, ibid., 6: 1893- 
4, 160. 

(14) C. Roberts, A manual of anthropometry. 

(15) Sack, Physical development of the children in the middle schools of 
Moscow, 1892. 

(16) F. W. Smedley, Rept. of the dept. of child-study and pedagogic 
investigation, reprint from 46th An. Rept. Brd. Educ, Chicago, 1899-1900. 
Also in U. S., 1902, i., 1095-1115. 

(17) F. W. Smedley, do.. No. 3, 1900-1901, also in U. S., 1902, i., 1115-1138. 

(18) G. West, Observations on the relation of physical development to 
intellectual abiUty, made on the school children of Toronto, Canada, in Science, 
n. s., 4: 1896, 156. 

(19) C. Wissler, The correlation of mental and physical tests, in P. R. 
M. S. 3: No. 6, 1901. Pp. 62. 



TEST 2 

Weight.^ — The general purpose of determining weight is similar 
to that of determining height, viz : to furnish an index of physical 
size or growth as a basis for correlation with other tests or observa- 
tions. 

Apparatus. — Accurate scales, joreferably of the type especi- 
ally devised for anthropometric work, which allow readings 
to be rapidly and accurately taken in the metric system, with units 
of 50 g. or twentieths of a kilogram (Fig. 5). If avoirdupois 



TEST 2: WEIGHT 



57 



scales are, used, they should be divided into tenths of pounds rather 
than into ounces. 

Method and Treatment of Results. — For accurate measure- 
ments, weight should be taken without clothes. Where this is 
impracticable, the weight of the clothes may be deducted by sub- 
sequent measurement. For some comparative purposes, however, 
the weight of the clothes may be neglected and the figures obtained 




A>. i Ml'.Ui UilLlUlL M ALES. 



The platform side of the beams is graduated metric to 100 kilos, by 50- 
gram divisions, and the other side avoirdupois to 200 pounds, by tenths 
of a pound. 



from the gross weight may be taken for computation, or these fig- 
ures, better yet, may be corrected by arithmetical computation 
based upon the weights of the clothes of a limited number of S's. 
We may form a tolerably accurate notion of the ' clothing error' 
by reference to investigations upon this point. Thus, according 
to W. S. Christopher (3), who ascertained the weight of the ordi- 



58 



ANTHROPOMETRIC TESTS 



nary schoolroom clothing of 121 Chicago children, chiefly in the 
month of May, "the average weight of the clothing of all the 
pupils was 5.5 per cent of the gross weight" (boys, 5.8 per cent; 
girls, 5.2 per cent.) These figures varied little with age: obese 
children wore clothing lighter in proportion to their weight than 
that worn by others, while "the most variable element in the cloth- 
ing was found to be the shoes, especially the shoes worn by the 
boys." Only a few children wear clothing that weighs more than 
7 per cent, or less than 4 per cent of their gross weight. 

Results. — (1) From the data of about 68,000 children in the 
cities of Boston, St. Louis, and Milwaukee, Burk (2) derives the 
norms reproduced in Table 12: the Chicago norms are reproduced 
in Table 13. 

TABLE 12 

Norms of Weight, in kg. (Burk) 



Approx. AgC; 6.5 



Boys...: .20.50 
Girls 19.6921.64 



10.5 11.5 12.5 13.5 1 14.5 15.5 



22 . 45 24 . 72|27 . 03 29 . 66:32 . 07,34 . SSLSS . 46 43 . 18 48 . 72 54 . SSj - 
23 . 81 26 03 28 . 53 31 . 52 35 . 7040 23 44 . 59 48 . 40 50 . 94 52 . 34 



TABLE 1.3 
Norms of Weight, in kg., with Clothing (Smedley) 



11.0 12.0 



14.0 I 15.0 



19 . 738;21 . 613 23 . 817 26 . 336 28 
18.87020.97423.01025.257 



707 31 . 22334 . 151 38 . 08442 . 696 47 . 993 53 
27 . 795bo . 662 34 373 38 974 44 219 48 . 161 



23857.384'61.283 
50.65252.386'52.923 



(2) As in the case of height, girls exhibit the prepubertal in- 
crease in weight some two years earlier than boys, and are for the 
years 12 to 15 heavier than boys of the same age. 

(3) Growth in weight, as in height, is subject to some lessen- 
ing of rate at 9 years for girls and at 11 for boys. 

(4) Boys continue to increase in weight after girls have prac- 
tically attained their maximal normal weight. Girls grow most 
rapidly from 10 to 15 years, boys from 12 to 17 years. 

(5) Mean variations in weight are largest during the period of 



TEST 2: WEIGHT 59 

fastest growth, which shows that not all individuals participate 
equally or evenly in the rapid growth of adolescence. 

(6) First-born children exceed later-born children in weight, 
at least during the period from 6 to 15 years, though the reverse is 
true of the weight at birth. The difference is slight, but very 
regular (Boas, 1). 

(7) Children of the non-laboring classes are as a group heavier 
than children of the laboring classes (Bowditch). 

(8) Children of American-born parents are heavier than those 
of foreign-born parents. 

(9) The correlation between weight and mental ability or pre- 
cocity is found to be positive by some investigators, negative by 
others, and indifferent by still others. Thus^ Porter (8) asserts 
very positivelj^ that "precocious children are heavier and dull 
children lighter than the mean child of the same age," and draws 
a further practical conclusion that "no child whose weight is 
below the average for its age should be permitted to enter a school 
grade beyond the average of its age, except after such a physical 
examination as shall make it probable that the child's strength be 
equal to the strain." Porter's conclusions are confirmed by Smed- 
ley (9) at Chicago. On the basis of the teacher's estimate of men- 
tal ability, Gilbert (4, 5), however, finds no constant relation be- 
tween weight and such ability, save that from 10 to 14 years the 
dull children are much heavier than the bright, while West (10), 
who used a similar basis, finds a negative correlation throughout. 

(10) Both Khne (6) and Smedley (9) fuid the mean weight of 
boys in truant schools to be less than that of boys in the public 
schools, save at the age of 10. 

(11) Porter concludes that the acceleration in weight preceding 
puberty takes place at the same age in dull, mediocre, and preco- 
cious children, but investigations in New York City seem to oppose 
this conclusion and indicate rather that puberty and pubertal 
growth is distinctly earlier in precocious children, i. e., that mental 
and physical precocity go hand in hand. 

(12)' Children with abnormalities are below the average in 
weight (MacDonald, 7). 

Notes. — It is not important to have scales which render possible 
a very fine measurement, such as fractions of an ounce, because the 



60 ANTHROPOMETRIC TESTS 

normal weight of any individual varies from day to day and from 
hour to hour during the day : the daily variation is, in the case of 
young men, as high as 0.3 kg. The author, in a long series of observa- 
tions conducted at the same hour daily, found gains and losses 
,of more than 1 kg. in 24* hours. It may not be amiss in this 
connection to point out the absurdity of attaching any sig- 
nificance to small gains or losses that are observed in weighings 
conducted at occasional and irregular intervals. Severe exercise 
may reduce the weight by a large amount; e.g., two hours of foot- 
ball practise may take off 2 or 3 kg. from a man who is not 
yet in training. It is well, however, for comparative purposes, 
to take weight measurements at approximately the same period 
of the day. 

REFERENCES 

(1) F. Boas, Growth of first-born children, in Science, n.s. 1 : 1895, 402-4. 

(2) F. Burk, Growth of children in height and weight, in A. J.P., 9: 1897-8, 
253. 

(3) W. S. Christopher, Report on child-study, reprint from An. Rept. 
Brd. Educ. Chicago, 1898-1899. 

(4) J. A. Gilbert, Researches on the mental and physical development of 
school children, in Yale S., 2: 1894, 40-100. 

(5) J. A. Gilbert, Researches upon school children and college students, 
in lowaS., 1: 1897, 1-39. 

(6) L. W. Kline, Truancy as related to the migratory instinct, in Pd.S., 
5: 1898, 381-420. 

(7) A. MacDonald, Experimental study of school children, etc., reprint 
of chs. 21 and 25 of U. S., 1899. 

(8) W. T. Porter, Physical basis of precocity and dullness, in Trans. 
Acad. Science St. Louis, 6: 1894, 263. 

(9) F. Smedley, Rept. dept. child-study and pedagogic investigation, 
No. 3, in Rept. Brd. Educ. Chicago, 1900-1901, also in U. S., 1902, i., 1115- 
1138. 

(10) G. West, Observations on the relation of physical development to 
intellectual ability, made on the school children of Toronto, Canada, in 
Science, n.s. 4: 1896, 156. 

TEST 3 

Diameter of the skull. — This measurement has been commonly 
conducted for the purpose of investigating the correlation 
between size of the head and general intelligence. It forms also 
one of the chief measurements undertaken in the Bertillon system 



TEST 3: DIAMETER OF THE SKULL 61 

for the identification of criminals. The following directions are 
adapted from Bertillon's account (1). 

A. MEASURING THE LENGTH OF THE HEAD 

Instrument.— Head calipers (Fig. 6). 

Method. — (1) Seat S with his right side toward a window, and 
stand facing his left side. Hold the left tip of the calipers firmly 
in place at the glabella (space between the eye-brows) with the 




FIG. 6. HEAD CALIPERS. 

tip of the instrument between the thumb and forefinger, and with 
these resting on the adjacent parts of the forehead to prevent the 
compass-tip from deviating. 

(2) Hold the calipers in an approximately horizontal plane so 
that the scale is fully lighted by the window, with the right tip 
projecting about one cm. beyond the finger-tips of the right hand. 
Keep the eyes fixed upon the scale; then bring the right tip down 
over the back and middle of the head until it has passed the most 
projecting point; then m^ve the tip upward again, making sure 
that it is well within the hair and in constant contact with the scalp ; 
continue these exploring movements so as to pass the maximal 
point two or three times, keeping the eyes constantly fixed upon 
the scale to detect this point. 

(3) Remove the calipers and set them by tightening the set- 
screw at the supposed length; take care to set them accurately 
within 0.5 mm. 



62 ANrHROPOMETRIC TESTS 

(4) Replace the calipers thus set and tightened, and again 
execute the exploring movements described in (2). If the setting 
is correct, the instrument will just touch the skin of the head at the 
maximal point, but will pass over it without undue friction and 
without necessitating pressure upon its arms: one millimeter too 
short will produce definite resistance at this point; one millimeter 
too long, a definite lack of friction. Practise will enable E to dis- 
tinguish the 'feel' of the correctly set instrument, and errors should 
not exceed 1 mm. 

B. MEASURING THE WIDTH OF THE HEAD 

Instrument.— Head calipers as above. 

Method. — Position of S, preliminary exploring movements, 
setting of the calipers, and subsequent verification follow the same 
general procedure as in the determination of the length of head. 
The following additional instructions are to be noted : 

(1) E stands behind S, and is careful to preserve an erect, 
symmetrical position, in order to ensure equal freedom with both 
elbows and a symmetrical position of the calipers. 

(2) Hold the calipers a short distance from each end; apply the 
tips first at the upper point of attachment of each ear; then raise 
them vertically and watch the scale to determine the point of great- 
est width, making several testing movements both upward and 
downward. 

(3) The true maximal diameter in most cases is not yet found, 
but lies in the same horizontal plane as the preliminary maximal 
point just determined, and about 3 cm. behind it. Hence, next 
move the calipers slowly back and forth two or three times in a 
horizontal plane and determine the true maximal point. 

(4) Set the instrument, as in the previous measurement, and 
verify the setting. In this verification, the caliper-points should 
describe a series of zig-zag movements, in order certainly to tra- 
verse the areas of maximal width (usually less than the size of a 
dime), which might not be traversed if the movements were cir- 
cular or too coarsely executed. 

Treatment of Results. — From the measurements of the length 
and width of head, the cephalic index may be computed readily by 



TEST 3: DIAMETER OF THE SKULL 



63 



multiplying the width by 100 and dividing by the length. This 
index is considered one of the most important of those used in 
anthropometry. By it, the type of head may be determined as 
follows : if the index is less than 75, *S is long-headed (dolichoceph- 
ahc); if 75-80.9, S is 'medium' (mesocephahc) ; if 81-86.9, S is 
broad-headed (brachycephalic) ; if 87 or over, S is excessively 
broad-headed (hyperbrachycephalic) . 

Results. — (1) Typical head measurements are those made by 
Boas, West, Chamberlain and others upon Worcester school chil- 
dren, and reported by West (7) : these are reproduced in Table 14. 

TABLE 14 

Diavielers of the Skull and the Cephalic Index (West) 



AVERAGE LENGTH 



/ERAGE WIDTH 



CEPHALIC INDEX 



Boys 



Boys 



Boyi 





mm. 


nun 


7nm. 


mm. 


% 


% 


5 


176 


174 


140 


138 


79.56 


79.40 


6 


177 


172 


142 


139 


78.94 


79.60 


7 


179 


175 


142 


140 


79.42 


80.02 


8 


180 


174 


143 


141 


78.71 


80.41 


9 


181 


176 


144 


140 


79.63 


79.71 


10 


182 


177 


145 


142 


80.30 


79.46 


11 


183 


180 


144 


142 


78.80 


78.90 


12 


183 


180 


145 


143 


79.40 


79.40 


13 


184 


181 


147 


145 


79.50 


79.60 


14 


1 187 


183 


147 


144 


78.60 


79.00 


15 


1 188 


184 


148 


146 


78.59 


78.99 


16 


1 191 


184 


149 


144 


77.81 


78.48 


17 


■ 189 


185 


150 


146 


78.34 


78.50 


18 


192 


186 


151 


147 


78.88 


79.36 


19 


192 


183 


150 


145 


78.33 


79.68 


20 


195 


182 


152 


147 


77.88 


79.41 


21 


192 


186 


153 


145 


79.29 


78.36 



(2) In boys, length of head continues to increase until the age of 
21; in girls, maxmial length of head is practically attained at 18. 
The growth, both of length and width of head, is very irregular, 
i.e., periods of growth alternate with periods of cessation of growth. 

(3) Boys' heads are longer and wider than those of girls through- 
out the whole period of gro^Hh, and consequently throughout life 



64 



ANTHROPOMETRIC TESTS 



(4) Width of head is greater in precocious than in dull children 
(Porter, 6, 7). One method of arraying data to show this prin- 
ciple is illustrated in Table 15, in which all the girls aged 12 and all 
the boys aged 10 are distributed according to their school grades. 
It is then seen that those children of a given age in an advanced 
school grade have, on the average, broader heads than those in a 
lower grade. 

TABLE 15 

Breadth of Head by School Grade (Porter) 





BOYS AGED 10 


GIRLS AGED 12 


SCHOOL GRADE 












Cases 


Average 


Cases 


Average 






mm. 




mm. 


I . . 


92 
408 


145.86 
146.73 


68 


_ 


II 


143.68 


Ill 


397 


146.48 


193 


144.77 


IV 


170 


147.21 


343 


144.94 


V 


- 


— 


217 


145.50 


VI 


- 


- 


89 


147.64 







(5) Binet, somewhat similarly, finds that the head of the unin- 
telligent is smaller than that of the intelligent child in all dimen- 
sions save in vertical diameter and distance from the base of the 
nose to the end of the chin, though the differences are but slight and 
somewhat uncertain. If, however, exceptionally bright children 
{enfants d'elite) are compared with exceptionally dull children 
(enfants arrieres), differences averaging 3-4 mm. or more appear, 
particularly in transverse dimensions, i.e., in breadth. Excep- 
tionally bright children distinctly surpass average children, but 
the latter do not differ so much from dull children. In brief, then, 
exceptionally bright children are characterized by unusually wide 
heads. 

(6) According to MacDonald, "dolichocephaly increases in 
children as ability decreases. A high percentage of dolichocephaly 
is, to a certain extent, a concomitant of mental dullness." "Un- 
ruly boys have a large percentage of long-headedness." 

(7) The measurements, by Engelsperger and Ziegler, of 238 boys 
and 238 girls of the entering classes (average age 6 years, 4.5 



TEST 3: DIAMETER OF THE SKULL 



65 



months) in the schools of Munich, furnish results that deviate 
somewhat from those just cited for American children, as is seen 
clearly by a comparison of Tables 14 and 16. 

It is of interest to note that no cases of dolichocephaly were found, 
but that these children were decidedly brachy cephalic. 

(8) Miss Lee found no correlation between the estimated skull 
capacity and the intellectual capacity of 60 men and 30 women. 

Notes. — ^Heads of unusual shape or size, irregular or deformed, 
should receive especial care in measurement, and a descriptive note 
should be appended to the record. 

Attempts to record the shape and size of the skull by means of 
the registering ' conformateur' used by hatters have usually been 
relinquished, because the hair interferes too much with exact de- 



Skull Dimensions and Proportions of Entering Classes at Munich (Engel- 
sperger and Ziegler) 





LENGTH 


BREADTH 


INDEX 




Mean 


Max. 


Min. 


Mean 


Max. 


Mm. 


Meso. 


Brachy. 


Hyperb. 


Boys 


170.35 
165.83 


185 
186 


148 
151 


146.34 
142.97 


160 
159 


133 
130 


% 

6.3 
6.7 


54^6 

45.8 


% 

39.1 


Girls 


47.5 







termination. This instrument might, however, be of service in 
preserving a rough 'picture' of heads of unusual size or propor- 
tions. 

Measurement of the head was formerly regarded as a very ob- 
vious means for the estimation of the size and proportions of the 
brain, and hence of intellectual ability, but it is easy to demon- 
strate that these relations obtain only in the gross. That is, brain 
size and form are only roughly indicated by the exterior dimensions 
of the head, while intelligence is conditioned primarily by the elab- 
orateness of the finer nerve structure and not (save in pathological 
cases of hypertrophy or developmental arrest) by the gross size 
or form of the brain. It is scarcely necessary to call attention 
to the absurdity, a fortiori, of the claims of phrenology. 



66 



ANTHROPOMETRIC TESTS 



REFERENCES 

(1) A. Bertillon, Signaletic instructions; including tlie theory and prac- 
tise of anthropometrical identification, Eng. tr. , Chicago and New York, 1896. 
Pp. 260. 

(2) A. Binet, Recherches sur la technique de la mensuration de la tete 
vivante, and four other articles on cephalometry, in A. P., 7: 1900 (1901) 314- 
429. 

(3) A. Engelsperger and O. Ziegler, Beitriige zur Kenntniss dcr physischen 
und psychischen Natur des sechsjilhrigen in die Schule eintretenden Kindes. 
Anthropometrisches Teil in E. P., 1: 1905, 173-235. 

(4) Alice Lee, Study of the correlation of the human skull, in Science, 
n. s. 12: 1900, 946-9. 

(5) A. MacDonald, Experimental study of children, etc., reprint of chs. 
21 and 25 of U. S., 1899. 

(6) W. T. Porter, The growth of St. Louis children, in Trans. Acad. 
Science St. Louis, 6: 1894, 263. 

(7) W. T. Porter, Physical basis of precocity and dullness, ibid., 160. 
{8"> G. West, Worcester school children; the growth of the body, head, 

and face, in Science, 21 : 1893, 2-4. 

TEST 4 

Girth of the skull.— This measurement is less in favor with 
investigators than those just described, because of the variable 
factor of the hair, just mentioned. 

Instrument.— Anthropometric measuring tape (Fig. 7). 

Method. — E stands at the right of ;S, who is seated. E holds 



1 llllllljllll 


'l"2l" 


i|ii3|iiii| 


'" 








15 




■liSBiiiB^^^^^^^ 



|| 



ANTHROPOMETRIC TAPE. 



(iraduateid tojt^Jjths of, inches on one side and millimeters on 
other, and fitted \yith^,a spi'ing handle to eliminate the pensonal vqni 
of different exami'ne'ts.' 



TEST 4: GIRTH OF THE SKULL 



67 



the tape with the thumb and forefinger of each hand at a length 
approximately that of the distance to be measured. He then 
lifts the tape over S's head, keeping it horizontal, and applies it 
about the head at such a height as to pass around the largest part — 
over the frontal prominences and over the occipital prominences. 
The tension of the tape is regulated by observation of the spring- 
indicator. 

Results. — (1) Measurements of the circumference of the head 
of 7953 boys and 8520 girls in Washington, D.C., by MacDonald 
(3) ' form the basis for the results embodied in Table 17. 

(2) The head circumference of boys is larger than that of girls 
save in the case of colored children. (Colored girls have a larger 
circumference of head at all ages than white girls.) In American 

table 17 
Circumference of the Head, in Inches (MacDonald) 



AGE 


BOYS 


GIRLS 


AGE 


BOYS 


GIRLS 


6 


20.48 


20.20 


13 


21.01 


20.95 


7 


20.45 


19.94 


14 


21.21 


21.18 


8 


20.51 


20.14 


15 


21.45 


21.28 


9 


20.61 


20.29 


16 


21.67 


21.38 


10 


20.73 


20.43 


17 


21.87 


21.55 


11 


20.82 


20.54 


18 


21.91 


21.60 


^ 12 


20.94 


20.78 









children, the measurements of girls most nearly approach those of 
boys at 13 and 14, or at the period when the girls excel in height 
and weight. 

(3) Children of the non-laboring classes have a larger circum- 
ference of head than children of the laboring classes. 

(4) Children with abnormalities are inferior in head circumfer- 
ence to normal children. 

(5) In an examJnation of 60 juvenile delinquents, Dawson (2) 
found the average circumference of head less than that of normal 
children of the same age : in 64 per cent of the cases studied, the 

^Consult MacDonald (pp. 1016ff.) for an extended discussion of the 
relation of circumference of head to sex, nativity, race, sociological 
condition and mental ability. 



68 ANTHROPOMETRIC TESTS 

circumference was from 1.7 to 5.2 cm. less than the mean for normal 
children. 

(6) According to MacDonald, as circumference of head increases, 
mental ability (as reported by the teacher) increases, provided that 
one and the same race be under consideration. Mobius (4), simi- 
larly, asserts that, at least in the case of normal (gesunde) adults, 
mental capacity tends to exhibit correlation with skull capacity. 
Bayerthal (1) measured the skull circumference of 234 boys and 153 
girls (ages 7.5 to 8.5 years) and related these measures with school 
standing by classifying both sexes into five groups, as "very good" 
(I), "good" (II), "good on the whole" (III), "satisfactory" (IV), 
and "more or less unsatisfactory " (V). The results tend to con- 
firm the existence of a positive correlation between skull circum- 
ference and general ability. Thus, the average skull-circumference s. 
Avere, for boys, 51.46, 50.93, 50.33, 49.60, and 49.60 cm., and for 
girls, 50.00, 49.83, 49.44, 49.16, and 48.84 cm., for the groups T 
to V, respectively. 

The same investigator found that in one class of 48 girls, who had 
been classed by their teacher into the three groups, good, average, 
and poor, the average skull circumference for these groups was 49.6, 
49.16, and 48.75 cm., respectively. 

REFERENCES 

(1) Bayerthal, Kopfumfang unci Intelligenz im Kindesalter, in E. P., 2: 
1906, 247-251. 

(2) G. E. Dawson, A study in youthful degeneracy, in Pd. S., 4 : 1S96, 221- 
258. 

(3) A. MacDonald, Experimental study of school children, etc., reprint 
of chs. 21 and 25 of U. S., 1899. 

(4) Mobius, Geschlecht und Kopfgrosse, Halle, 1903. 



CHAPTER V 

Tests of Physical and Motor Capacity 

The title 'physical and motor capacity' is here used as a Conveni- 
ent and practical phrase to cover a number of tests which have 
often been classified under diverse rubrics, such as strength tests, 
motor tests, physical tests, tests of physiological condition, etc. 
All of the tests here described differ from the anthropometric tests 
of Chapter IV in that they measure not mere size or dimension, but 
functional, especially muscular, capacity. They differ from the 
tests of Chapter VI, many of which might equally well be said to 
measure physiological condition or capacity, e.g., the test of visual 
acuity, in that they are primarily tests of motor, rather than of sen- 
sory capacity. 

The first test described, that of vital capacity (often loosely 
termed lung capacity) is, perhaps, not so obviously a test of muscu- 
lar efficiency as are the four strength tests that follow. It is, how- 
ever, clearly a test of physical capacity dependent upon movement. 
The tests of quickness, accuracy, and steadiness of movement are 
frequently placed in a class by themselves under the rubric 'motor 
tests.' but they are easily subsumed under the caption here 
employed. 

Reaction-time would by many be considered a test of quickness 
of movement; but it is so largely dependent upon complex psycho- 
logical conditions, particularly upon the instructions, the direction 
of attention, and the type of stimulus employed, that it belongs 
rather to the experimental examination of action than to the meas- 
urement of physical capacity as such.^ 

These tests of physical and motor capacity have become promi- 
nent chiefly because of their employment in the study of the corre- 

^ See an article by the writer, "Reaction-Times as a Test of Mental Abil- 
ity," in A. J. P., 15: 1904, 489. 



70 



PHYSICAL AND MOTOR CAPACITY 



lation of physical and mental abilitJ^ For this purpose they are 
commonly used in conjunction with the anthropometric tests 
already described and with various tests of general intelligence or 
mental ability to be described later. 

These tests have also an obvious and direct application in the 
stud}^ of various problems of hygiene, physical culture, etc. 

TEST 5 

Vital capacity.— Vital capacity, also termed breathing capacity 
and differential capacity, is the maximal volume of air that can be 




FIG. S. WET SPIROMETER. 

Graduated in cubic inches and cubic decimeters. 



expired after taking a maximal inspiration. It is not identical with 
lung capacity, because a certain amount of air, termed the residual 
air, always remains in the lungs. 

Vital capacity is considered an important index of general physi- 



TEST 5: VITAL CAPACITY 71 

cal condition and capacity, and has, accordingly, found a place in 
nearly all measurements of school children in which the physical 
status has been examined. It is affected by sex, age, stature, pos- 
ture, occupation, amount of daily physical activity, and by disease, 
and may be markedly increased {e.g., 300 cc, in three months) by 
various forms of physical exercise which demand active respiration. 
The ratio of vital capacity to weight is termed the vital index 
and is held to be of extreme significance, because it expresses the 
balance between bodily size and the rate and completeness with 
which oxidization of the blood is, or may be, effected. A high vital 
index is undoubtedly a preventive of auto-intoxication, gives 
increased resistance to disease, and is the root of endurance under 
effort. Thus athletic training consists primarily in the reduction 
of weight and the increase of breathing capacity. 

TABLE 18 
Norms of Vital Capacity, in Cubic Centimeters (Smedley) 



AGK 


BOTS 


GIRLS 


.G. 


BOT9 


GIRLS 


6 


1023 


950 


13 


2108 


1827 


7 


1168 


1061 


14 


2395 


2014 


8 


1316 


1165 


15 


2697 


2168 


9 


1469 


1286 


16 


3120 


2266 


10 


1603 


1409 


17 


3483 


2319 


11 


1732 


1526 


18 


3655 


2343 


12 


1883 


1664 




L_„._ 





Apparatus. — Spirometer, preferably of the wet type (Fig. 8) 
fitted with detachable wooden mouth-piece. Extra mouth- 
pieces. 

Method. — See that S's clothing is perfectly loose about his neck 
and chest. Instruct him to stand upright, to take as full an inspira- 
tion as possible, and then to blow, not too rapidly, into the spirom- 
eter. Also caution him to take care that no air escapes about the 
mouth-piece. 

Two or three trials may be allowed, and the best record set down. 

After S's record is made, discard the mouth-piece and insert 
a new one into the rubber tube. 



72 PHYSICAL AND MOTOR CAP.\C1TY 

Results.— (1) The norms of vital capacity embodied in Table 
18 are those established by Smedley (6) at Chicago. 

(2) The relation between weight and vital capacity, i.e., the 
vital index, presented in Table 19, is that fomid by Kotelmann (4), 
also given by MacDonald (5). The ratio expresses the relation in 
terms of kg. of weight and cc. of vital capacity. It will be seen 
that the weight of the body normally increases with age somewhat 
faster than the vital capacity. If height be similarly treated, it will 
be fomid, on the contrary, that vital capacity increases with age 
faster than it increases. 

(3) All investigators agree that boys have a larger vital capac- 
ity than girls at all ages, and that men, similarly, have a larger capac- 

TABLE 19 
Value of the Vital Index, token Weight is Taken as Unity {Kolelniann) 

i 1; ' 

AGE INDEX 'age INDEX L AGE INDEX AGE INDEX 



9 


69.32 


12 


! 67.51 1 


15 


63.18 


IS 


64.28 


10 


69.37 


13 


I 66.75 


16 


65.94 


19 


66.22 


11 


1 69.18 


14 


1 64.07 j 


17 


1 65.77 |l 


20 


i 65.01 



ity than women. Even if we compare men and women of the same 
height, the former surpass the latter by about the ratio 10 : 7.5. 

(4) The average capacity for adults is computed b}^ Vierordt 
to be for men 3400 cc. (a figure noticeably lower than the Chicago 
norms for boys in later adolescence) and for women 2400 cc. 

(5) The norm is conditioned by height. For each centimeter 
of increase or decrease of stature above or below the mean, there is 
a corresponding rise or fall of the vital capacity, amounting in men 
to 60 cc, in women to 40 cc. This correlation with height varies 
somewhat at different ages. Thus, according to Wintrich, the 
average vital capacity for each centimeter of height is from eight to 
ten years, 10 cc, from 16 to 18 years, 20.65 cc, and at 50 years, 21 cc. 

(6) In boys, growth in vital capacity is slow and steady during 
the years 6 to 12, but very marked during the next four years, 
whereas in girls the most rapid increase is during the years 11 to 14. 
In both sexes, these periods of rapid growth coincide with the peri- 
ods of rapid growth in height and weight. 



TEST 5: VITAL CAPACITY 73 

(7) Beyer (1), from his study of naval cadets, concludes that the 
maximal vital capacity is reached at 19, but other authorities place 
the maximum at 35, with an annual decrease of about 32 cc. there- 
after, up to the age of 65. 

(8) The most marked individual differen ces appear at the time 
when the period of most rapid gtowth terminates (Smedley, 7). 

(9) Vital capacity is proportionately reduced in men who live a 
sedentary life. It is also reduced by any circumstance which inter- 
feres with the free expansion of the thorax, such as tight clothing, 
tuberculosis of the lungs, visceral tumors, etc. 

(10) The correlation of vital capacity and mental ability is 
indifferent or negative according to Gilbert (2, 3), who found no con- 
stant relation, save that from 10 to 15 years duller children have the 
larger capacity. On the other hand, Smedley (6, 7) found a posi- 
tive correlation between school standing and vital capacity, whether 
he took the distribution through the grades of all pupils of a given 
age, or computed the average school-grade of those who stood at 
various precentiles of vital capacity, or compared those at and above 
grade with those below grade at each age. Moreover, the same 
investigator found that pupils in the John Worthy School (incor- 
rigibles, truants, etc.) were, from the age of ten up, inferio. in 
vital capacity to children in the other schools, and that the in- 
feriorit}^ became more noticeable with age. 

Notes. — The dry spirometer is less expensive than the wet in 
first cost, and is more portable, but it has the disadvantage of get- 
ting out of repair easily. Its readings are apt to run slightly higher 
than those of the wet spirometer. 

The mouth-piece of the ordinary spirometer forms an excellent 
medium for the dissemination of bacteria. For this reason the 
detachable mouth-pieces are imperative if hygienic conditions are 
to be assured. 

There is a certain knack in making a maximal spirometer record ; 
some children may exhibit it; others not. In particular, to get 
a good record, the expiration must be neither too fast nor too slow, 
and an extra effort must be made just at the end of both inspiration 
and expiration to utilize the available lung-capacity to the utmost. 



74 ' PHYSICAL AND MOTOR CAPACITT 



REFERENCES 



(1) H. G. Beyer, The growth of United States naval cadets, in Proc. 
U. S. N. Inst., 21: No. 2, 1895. 

(2) J. A. Gilbert, Researches on the mental and physical development of 
school children, in Yale S., 2: 1894, 40-100. 

(3) J. A. Gilbert, Researches upon school children and college stu- 
dents, in Iowa S., 1: 1897, 1-39. 

(4) L. Kotelmann, Die Korperverhaltnisse der gelehrten Schliler des 
Johanneums in Hamburg, in Zeits. d. Konigl. Preus. statist. Bureaus, 1879. 

(5) A. MacDonald, Experimental study of school children, etc., reprint 
of chs, 21 and 25 of U. S., 1899. 

(6) F. Smedley, Rept. dept. child-study and pedagogic investigation, 
reprint from 46th An. Rept. Brd. Educ. Chicago, 1899-1900. Also in U. S., 
1902, i., 1095-1115. 

(7) F. Smedley, do., No. 3, 1900-1901. Also in U. S., 1902, i., 1115-1138. 

TEST 6 

Strength of grip. — This test has been used to secure an mdex of 
general bodily strength, to secure an index of righthandedness^ (in 
conjunction with Tests 10 to 12), and for comparative purposes 
generally. It may be modified to secure an index of endurance or 
fatigue (Test 9), or combined with other forms of strength measure- 
ment (Tests 7 and 8). 

Apparatus.— Improved form of Smedley's dynamometer (Fig. 
9). Millimeter rule. 

Method. — With the millimeter rule, measure the distance from 
where S's thumb joins his hand to the end of his fingers. Adjust 
the dynamometer by whirling the inner 'stirrup' until the scale on 
the outer stirrup indicates one-half this distance. This should 
bring the second phalanx to bear against the inner stirrup, and will 
ordinarily prove to be the optimal adjustment; if not, it may be 
modified to suit S's inclinations. Then set the instrument by 
means of the clutch, so that the inner stirrup cannot twist while in 
use, and record the adjustment by reference to the scale upon the 
stirrup. 

' The terminology of right and left-handedness is at present somewhat 
confused (Cf . E. Jones, in P. B., 6: April, 1909). The terms 'index of unidex- 
terity' and 'index of dextrality' have been used by some writers as equivalent 
to 'indexof righthandedness.' 'Dextrality' is here used to indicate the supe- 
riority of one hand (whether right or left) over the other. 



TEST 6: STRENGTH OF GRIP 



75 



Illustrate the use of the instrument to S: especially make clear 
that the lower pointer will register the grip, so that he does not 
have to continue his effort while the scale is read. 

Allow three trials with each hand, right and left alternately, but 
introduce a brief pause, say 10 sec, between each trial to avoid 
excessive fatigue. Have S exert his maximal grip, and in each trial 
encourage him to do his best. Record the amount registered at 
each trial; but, for ordinary purposes, use in subsequent computa- 
tion only the highest record for each hand. 




FIG. 9. DYNAMOMETER AND DYNAMOGRAPH, AFTER SMEDLEY, IMPROVED. 



Results. — (1) Tests of 2788 boys and 3471 girls in Chicago 
(9) with the Smedley dynamometer yielded the norms of Table 20. 

(2) Boys are uniformly stronger than girls, and men stronger 
than women. 

(3) The divergence between the sexes becomes marked at 
puberty, with the appearance of other sex traits. 

(4) Individual variation in strength is more evident in early 
adolescence than at any other time. 

(5) In his study of Washington school-children, MacDonald (6) 
found no correlation between strength of hand and mental ability, 



re 



PHYSICAL AND MOTOR CAPACITY 



but rather a dependence of strength upon sociological condition, 
i.e., children of the poorer classes work outside of school hours and 
thus develop their strength. Since from these and other causes, the 
percentage of dull children in such a group is liable to be large, this 
accounts for the indications in his results that dull children tend to 
surpass bright or average children in strength. Yet Schuyten (7) 
concludes that the children of well-to-do parents are stronger than 
the children of poor parents. 



TABLE 20 

Norms of Strength of Grip, in kg. (Smedley) 





BOYS 


GIRLS 




Rt. Hand 


Lt. Hand 


, Rt. Hand 


Lt. Hand 

■ 


6 

8 


9.21 
10.74 
12.41 
14.34 
16.52 
18.85 
21.24 
24.44 
28.42 
33.39 
39.37 
44.74 
49.28 


8.48 
10.11 
11.67 
13.47 
15.59 
17.72 
19.71 
22.51 
26.22 
30.88 
36.39 
40.96 
45.01 


' 8.36 
1 9.88 
11.16 
12.77 
14.65 
16.54 
18.92 
21.84 
24.79 
27.00 
28.70 
29.56 
29.75 


7.74 
9.24 
10.48 


9 


11 97 


10 


13.72 


11 

12 

13 

14 

15 


15.52 
17.78 
20.39 
22.92 
24.92 


16 


26.56 


17 


27.43 


18 


27.66 







(3n the other hand. Miss Carman (3), from measurements of the 
grip of 1507 boys and girls aged 10 to 19 years, found that bright 
children exceeded dull children by an average of 3 kg. with the right, 
and 1 kg. with the left hand. 

In Chicago (9, 10) the existence of a positive correspondence 
between strength of grip and class-standing was shown by three 
different methods, viz: by the distribution of 12-year old pupils by 
grades, by comparing the grip of those at and above grade with the 
grip of those below grade at each age, and by computing the aver- 
age number of school grades that had been made by the various 



TEST 6: STRENGTH OF GRIP 77 

percentile groups (in strength), after sex and age had been ehmin- 
ated. 

Schuyten, who estimated inteUigence by school grade in rela- 
tion to age, also found that those who are most intelligent are 
strongest. 

(6) Dawson (5) found that juvenile delinquents have a mean 
strength of grip slightly less than normal children and that 56 per 
cent of them are inferior to the normal by from 1.32 to 11.82 kg. 
Similarly, boys in the school for incorrigibles and truants at Chi- 
cago are, at every age from 9 to 17 and with either hand, less strong 
than normal boys and this discrepancy increases very decidedly 
with age, e.g., from 96.8 per cent of the norm at the age of 9 to 63.2 
per cent of the norm at the age of 17. 

(7) The index of righthandedness, i.e., the percentage of strength 
of the left hand compared with the right, will be found to range, for 
any ordinary group of school children, between 91 and 96 per cent. 

(8) Dextrality, i.e., superiority of one hand over the other, is evi- 
dent when the child enters school, but becomes increasingly evident 
as maturity approaches, and especially at puberty, so that a height- 
ened difference in the strength of the hands may be regarded as one 
of the characteristic indications of pubertal change. 

(9) There is a positive correlation between dextrality and intellec- 
tual ability (Smedley, 9), i.e., dull pupils are more nearly ambi- 
dextrous than average, and average than bright, pupils, while the 
John Worthy schoolboys are still more nearly ambidextrous than 
the dull pupils of the regular schools. 

(10) The degree of dextrality is greatest in the strongest children 
and least in the feeble, so that the latter may be said, as it were, to 
have two left hands (Binet and Vaschide, 1). 

(11) If the test is taken under stimulating conditions, such as 
competition, personal encouragement, public announcement of 
records, etc., Binet and Vaschide found that the average grip was 
increased about 3 kg., or so much that the left hand surpassed the 
previous record of the right hand made without such incitement. 
Similarly, Schuyten (8) found that ennui, or loss of interest in suc- 
cessive tests, is sufficient to obscure the fatigue-effect of a school 
session. 

(12) The exertion of maximal strength is commonly accom- 



78 PHYSICAL AND MOTOR CAPACITY 

panied by characteristic poses, attitudes, facial contortions, grima- 
ces, etc., which are, in general, evidences of the escape of uncontrol- 
led energy through various motor paths. There appears to be an 
inverse relation between the strength and efficiency of the subject 
and the number and extent of these waste movements; these are 
correspondingly more evident when the muscles tire and aS^ is unable 
to accomplish what he is attempting. In particular, a sort of fool- 
ish laugh is characteristic of this muscular inefficiency.^ 

Notes.— The chief objections which have been made to the 
employment of the dynamometer are (1) that it is painful, particu- 
larly if a series of grips is taken, (2) that some aS's suffer from sweat- 
ing of the hands, especially when excited, and that this causes the 
instrument to slip in their grasp, (3) that a wrong manner of hold- 
ing the instrument may reduce the record, e.g., by as much as 10 
kg., (4) that, owing to the large number of muscles concerned, a 
lack of proper coordination in their contraction may lower the record. 

The painf ulness of the dynamometer can be largely eliminated by 
proper construction; the Smedley instrument is much better than 
the Collin elliptical form so commonly used heretofore. Moreover, 
if an extended investigation is to be undertaken, inurement to the 
pressure is rapidly developed (Bolton and Miller). 

For the ascertainment of strength of grip, excessive perspiration 
can be avoided by simply drjdng the hands with a towel whenever 
necessary. 

The proper holding of the instrument is also largely dependent 
on proper construction, and in this respect, again, the Smedley 
instrument, with its adjustable grip, is a distinct improvement over 
other forms. 

The last objection is not to be seriously considered, first, because 
hand-grip is one of the most common forms of coordinated move- 
ment and is well organized early in childhood, and second, because 
experience shows that most S's can make their maximal record in 
three attempts at least. - 

' For a description, with photographic reproductions of tlaese motor 
automatisms of effort, consult Binct and Vaschide. 

^ If, for any reason, E considers these sources of error not eliminated, it 
may be necessary to select a number of >S's and coach them in the use of 
the dynamometer until they can either avoid the errors, or report to E 
when they occur. J. Claviere (4) asserts that to employ only those S's who 
are thus trained in the use of the instrument is an indispensable condition 
for successful dynamometry. 



TEST 6: STRENGTH OF GRIP 79 

In any extended investigation, E should take steps to test the cali- 
l)ration of the dynamometer occasionally. For this purpose, the 
instrument is held securely in a vise or other support and a series of 
weights are hung upon the stirrup while the scale-readings are com- 
I)ared with the actual weighting. 

For many purposes it is desirable to combine strength of grip 
with strength of back and strength of legs by adding the data 
secured in these three tests. 

The advantages and disadvantages of using a series of grips in 
place of a single one are discussed in Test 9. 

REFERENCES 

(1) A. Binet and N. Vaschide, Experiences de force musculaire et de fond 
chez les jeunes gargons, in A. P., 4: 1897 (1898), 15-63. See also pp. 173- 
199, 236-252, 295-302. 

(2) T. Bolton and Eleanora Miller, On the validity of the ergograph as a 
measurer of work capacity, in Nebraska Univ. Studies, 1904. Pp. 79 + 128. 

(3) Ada Carman, Pain and strength measurements of 1507 school children 
in Saginaw, Michigan, in A. J. P., 10: 1899, 392-8. 

(4) J. Claviere, Le travail intellectuel dans ses rapports avec la force 
musculaire mesuree au dynamometre, in A. P., 7: 1900 (1901), 206-230. 

(5) G. E. Dawson, A Study in youthful degeneracy, in Pd. S., 4: 1896, 221- 
258. 

(6) A. MacDonald, Experimental study of school children, reprint of 
chs. 21 and 25, U. S., 1899. 

(7) M.-C. Sch uyten, Les variations de la force musculaire et le developpe- 
mcnt intellectuel des eleves; summarized by A. Binet, in A. P., 9: 1902 
(1903), 448-9, from Pajdologisch Jaarboek, Ghent, 1902. 

(8) M.-C. Schuytcn, Comment doit on mesurer la fatigue des ecoliers, 
in Ar. P., 4:1904, 113-128. 

(9) F. Smedley, Rept. dept. child-study and pedagogic investigation, 
reprint from 46th An. Rept., Brd. Educ. Chicago, 1899-1900. Also in U. S., 
1902, i., 1095-1115. 

(10) F. Smedley, do.. No. 3, 1900-1901. Also in U. S., 1902, i., 1115-1138. 

TEST 7 

Strength of back. — This test, together with the following, has 
l)een extensively used, in securing an index of the general bodily 
strength of college students, but has not been applied in most exam- 
inations of school children. A fairer index of strength may, how- 
ever, be gained by its use in combination with strength of grip. 



»U PHYSICAL AND MOTOR CAPACITY 

Instrument. — Back and leg dynamometer (Fig. 10). 

Method. — S stands upon the footrest of the instrument, which £^ 
should then adjust by lengthening or shortening the chain, so that 
.S'sbody is inclined forward at an angle of about 60 degrees (Fig. 11). 
S should then take a full breath and give a hard lift, mostly with the 
back and without bending the knees. Two or three trials may be 
recorded, and the best record used subsequently in computation. 




FIG. 10. BACK AND LEI! DYNAMOMP^TER. CAPACITY, 700 KG. 



Results. — (1) On the use of this and the succeeding test, with 
quantitative results as obtained in college gymnasiums, etc., consult 
Hastings (3), Sargent (4, 5), Seaver (6) and other author! ties already 
cited under anthropometry in general. 

(2) Binet and Vaschide (1) found the lift (force rennle) of 37 
boys aged from 12 to 14 years to average 77 kg., with a maximum of 



TEST 7: STRENGTH OF BACK 



81 



121 kg., and minimum of 56 kg. With 40 young men averaging 18 
years of age, the same investigators (2) obtained for the average 
146.64, for the maximum 187, and for the minimum 101.6 kg. 
Hastings (p. 71) publishes measurements of 5000 young men (17- 
30 years) whose strength of back averages 150.9 kg., P. E. 22.1, with 
a minimal record of 74.5 and a maximal record of 227.3. 

(3) Back lift is roughly about 3.2 times the strength of the right 
hand. 





y^r 
'"^J 


T 

■ ! 

. i 

1 


1 








i 




.Vi 1 


i '• 




T 'i 


M 




•/)■ 1 1 






^- 





FK;. 11. BACK AND LEfi DYNAMOMETER, AS USED FOR STRENGTH OF BACK- 

From D. Sargent, Anthropometric Apparatus. 



Note. — The adjustment of the chain may, with advantage, be 
based upon /S's height. For this purpose, E may work out an empir- 
ical table of relations between height and the length of chain neces- 
sary to give the required position. 



PHYSICAL AND MOTOR CAPACITY 



REFERENCES 



(1) A. Binet and N. Vaschide, Experiences de force musculaire et de fond 
chez les jeunes gargons, in A. P., 4: 1897 (1898), 15-63. 

(2) A. Binet and N. Vaschide, La mesure de la force musculaire chez les 
jeunes gens, ibid., 173-199. 

(3) W. Hastings. A manual for physical measurements for use in normal 
schools, public and preparatory schools, etc., Springfield. Mass., 1902. Pp. 
112. 

(4) D. Sargent, Strength tests and strong men at Harvard, in J. Boston 
Soc. Med. Science., No. 13, 1896-7. 

(5) D. Sargent, Anthropometric apparatus, etc., Cambridge, Mass., 1887. 
Pp. 16. 

(6) J. Seaver, Anthropometry and physical examination. New Haven, IStO. 

TEST 8 

Strength of legs. — This strength test is to be used m conjunction 
with strength of grip and strength of back. The best records in each 
of these three tests maj^ be added, to secure an index of general bod- 
ily strength. 

Instrument. — Back and leg dynamometer. 

Method. — S stands upon the foot rest of the instrument with his 
trunk and head erect and his chest well thro^vn out, but with the 
knees well bent (Fig. 12). E then adjusts the instrument so that 
the handle, when grasped by S, rests against his thighs. S should 
then take a full breath and give a hard lift, mostly with the legs, 
using the hands to hold the handle in place. Allow two or three 
trials as before. 

Results. — Strength of legs is commonly about 26 per cent greater 
than strength of back. Thus, the 5000 men whose records are 
embodied in Hastings' table have a mean streng-th of legs of 189.5 
kg., P. E., 35.3, with a minimal record of 102.2 kg. and a maximal 
record of 276.8 kg. 

TEST 9 

Endurance of grip. — The object is to test the capacity of S to 
exert maximal muscular exertion, not in a single effort, as in Test;^ 
6, 7, and 8, but during a period of one minute : the test is thus vir- 
tually identical with the endurance tests commonly undertaken b}' 
means of the ergograph. 



TEST 9: ENDURANCE OF GRIP 



83 



Since Mosso's studies of muscular fatigue (31), the ergograph has 
been extensively employed, not only by physiologists, but also by 
psychologists and by investigators of school children. The form of 
the apparatus and the conditions of the test have been widely varied, 
and the numerous factors which affect the test have been exhaust- 
ively discussed. In general, the purposes for which the ergograph 
test has been employed may be summarized thus: (1) to study the 





ii' 


T 

\ 


ii 


I ■ ■! 






-i 










A i 










; ^ 1 

' i ' 
1 i 


\^ 




% 


"'"';--"■• '- 


-^ [^^^--^^^ 



FIG. 12. 



BACK AND LEG DYNAMOMETER, AS USED FOR STRENGTH OF LEGS. 

From D. Sargent, Anthropometric Apparatus. 



physiology of muscular contraction, (2) to detect the presence and 
to examine the nature and extent of muscular fatigue, (3) like the 
strength tests, to gain an index of physical capacity or endurance 
under varying conditions, e.g., as affected by stimulants, narcotics, 
poisons, exercise, varying diets, etc., (4) to secure an index of right- 
handedness, (5) to discover whether physical fatigue is general or 
local, (6) to discover how mental work affects physical capacity, and, 
in particular, whether mental fatigue is reflected in muscular fatigue 



84 PHYSICAL AND MOTOR CAPACITY 

with such clearness that its existence and degree may be ascertained 
by the examination of some restricted group of the muscles, and (7), 
on the assumption that physical capacity does measure directly the 
condition of mental efficiency, to determine the so-called diurnal 
'course of power.' 

As just intimated, the question of the applicability of the ergo- 
graph to these varied purposes raises a large number of problems, 
in particular that of the nature of fatigue. Since mental fatigue is 
reducible to physiological fatigue, the main point at issue is that of 
the precise nature of the latter. 

The relative fatiguability of the structures concerned in physiologica 
fatigue, i. e. of muscle, nerve fiber, and nerve cells, is a complex and dis- 
puted question. We know that the fiber, in comparison with other tissues, 
is extremely resistant to fatigue, either because the catabolic changes are 
minute, or, more probably, because they are at once compensated by ade- 
quate anabolism. 

It has long been thought that the brain and spinal cord are much more 
susceptible to fatigue than the muscle, and consequently, the non-fatigu- 
ability of the nerve fiber has led most adherents of the neurone theory 
to look for the locus of nerve fatigue in the cell-body, in which, as has been 
shown by Hodge and others, excessive fatigue is accompanied by marked 
histologic changes. 

On the other hand, Sherrington denies central fatigue to the cell-bodies, 
and locates it in the synapse (point where one neurone comes into functional 
relation with the next in the series), and assumes that this acts, like the 
motor end-plate (point where the neurone comes into functional relation 
with the muscle fiber), as a sort of safety' -fuse to prevent overwork and 
damage to the tissues. Sherrington's experiment indicates that if a single, 
afferent tract is stimulated through several afferent tracts, the muscular 
contraction can be continued, when one afferent tract is exhausted, by re- 
course to the others. Other experiments, particularly those of Mile. Jote/ko, 
indicate that, compared with the terminal organs, the reflex mechanism of 
the spinal cord is practically indefatigable. If we extend this conclusion 
to the higher centers of the brain, we arrive at a peripheral theory of fatigue. 
Prominent evidence against such a conclusion has long been found in the 
observation that a muscle exhausted by volitional effort will still respond to 
electrical stimulation, but this observation is now discredited by the experi- 
ments of Kraepelin, G. E. Miiller (32), R. Mliller (33), Storey (38), and others, 
who have shown that the electrical stimulation in this case really sets in 
play a different set of muscles, and that, if a single muscle, like the abductor 
indicis, be properly isolated, the recuperation is not present. 

"In view of these results and others," says Lee (25) "I am inclined to the 
belief that when we perform continued muscular work, our muscular system 



TEST 9: ENDURANCE OF GRIP 85 

fatigues before our central nervous system. Moreover, the same results 
make it probable that the brain and the spinal cord are, like the nerve 
fiber, resistant, and they throw a certain measure of doubt on all supposed 
proofs of central fatigue" (25, pp. 179-180). 

The question of mental fatigue, induced by intellectual work, thus 
becomes perplexing. That it is a reality cannot, of course, be denied. Very 
likely even this type of fatigue is largely peripheral in origin, but how much 
is peripheral and how much central cannot as yet be stated. The usual 
assumption that brain fatigue is local in character seems due in part to the 
fact that the presence of fatigue is first indicated usually by the characteris- 
tic feeling of fatigue, but we may conclude that this feeling, like the corre- 
sponding feeling of effort, is primarily of peripheral origin, the consequence 
of the depressant action of certain toxic products, such as sarco-lactic acid, 
carbon dioxid, etc, which affect the muscular system in particular. 

Since these toxic products, at least when present in considerable amounts, 
are carried by the blood throughout the body, it follows that decided fatigue 
is not confined to the tissues in which it arises (as Mosso showed in his 
experimental transfusion of the blood of a fatigued, into the veins of a fresh 
dog). Those who argue that fatigue is not general, but local, at least when 
not excessive, usually base their conviction upon the evidence of certain 
experimental studies which seem to indicate that well-defined local 
fatigue may exist without lowering perceptibly the functional capacity of 
other portions of the organism. 

It may not be incorrect to assume that the toxic products are most detri- 
mental in the locality where they are produced, yet may have, in time, a dis- 
tinct general influence, and, similarly, that the reflex effects of fatigue, 
whether exciting or depressing, are partly local and partly general: the 
consumption of cell material, on the other hand, is more distinctly a local 
phenomenon (Bergstrom, 2). 

In understanding the nature of mental fatigue and in distinguishing 
between general and local fatigue, it is helpful to separate the objective 
fatigue (Ermudung), i. e., actual functional inefficiency, from 'weariness' 
{Miidigkeit) i. e., the subjective experience of ennui, loss of interest, or dis- 
inclination to work.^ Thus, it is weariness rather than fatigue which dis- 
appears when one's occupation is changed: weariness is fluctuating, uncer- 
tain, and largely dependent upon the general conditions under which work 

* Again some physiologists would differentiate fatigue and exhaustion: 
fatigue is, for them, a merely temporary reduction of efficiency, due to the 
accumulation of waste products, while exhaustion is a more serious condi- 
tion due to lack of adequate nutrition. For a discussion of the nature of 
fatigue and of other factors such as practise, ennui, warming-up, spurt, etc., 
that complicate the determination of the fatigue curve, consult Kemsies 
(21), Kraepelin (22, 23), Thorndike (40) Ellis and Shipe (14) , Bergstrom (2), 
Miiller (33), Loeb (27), Aars and Larguier (1), Hough (19), Bettman (3), 
Rivers and Kraepelin (35), Weygandt (41), Lin,dley (26). An authorita- 
tive summary of the problem from the point of view of the physiologist will 
be found in Lee (25) . 



86 PHYSICAL AND MOTOR CAPACITY 

is being done, while fatigue increases more or less steadily and progres- 
sively during our waking moments. If weariness is often specific, fatigue 
may be more often general and operative to reduce the available energy for 
work (Leistutigsfdhigkeit) in any direction. 

These considerations make it evident that, while the relations 
between mental fatigue and muscular energy are still obscure, we 
may hope, in principle, to secure some index of the former by our 
measurements of the latter. If the ergograph is to be employed for 




FIG. 13. STOP-WATCH. 

exact laboratory experimentation, there is no doubt but that the 
instrument must be of elaborate construction and the technique 
equally refined. The development of the ergograph itself from the 
relatively simple instrument of Mosso to such a complicated appa- 
ratus as that devised by Bergstrom is symptomatic of this gradual 
refinement of method and progressive analysis of the modifying 
factors.^ 

' Consult also Cattell (11), Franz (15), Binet and Vaschide' (5), Binet and 
Henri (4), Bolton and Miller (10), Hirschlaff (17), R. Miiller (33). 



TEST 9: ENDURANCE OP GRIP 87 

But while such problems as the merits of spring vs. weight load- 
ing, the relative capacity of a muscle working by isometric and by 
isotonic contractions, or the most reliable method of isolating the 
working muscle may be of paramount importance for laboratory 
investigation, it does not seem, on this account, absolutely impos- 
sible, as some writers assert, to secure valuable results for compara- 
tive purposes from large numbers of subjects by the use of simpler 
apparatus and less rigorous teclmique, — provided, of course, that 




FIG. 14. METRONOME, WITH MERCURY CUPS FOR ELECTRIC CONTACT. 

the conditions of experimentation are kept as constant as possible 
for different subjects and for the same subjects at different times. ^ 
For this reason, the test which is here described is suggested as a 
practical substitute for the more cumbersome and complicated ergo- 
graph. 

Apparatus. — Smedley dynamometer (Fig. 9) . Stop-watch (Fig. 
13). Metronome (Fig. 14). [If desired, a kymograph, (Fig. 15) 

' In general, it may be expected that minor variable errors will, in a 
sufficiently long series of tests, be distributed according to the law of 
chance. Possibly, some portion of the dispute concerning the value of 
ergograms arises from the fact that certain experimenters have worked 
upon large numbers of subjects, while others have contented themselves 
with curves obtained from a single individual. 



88 



PHYSICAL AND MOTOR CAPACITY 



with drum support (Fig. 16) and other accessories, and a Marey 
tambour (Fig. 17), or the Mosso ergograph (Fig. 18).] 

Two methods are described: one calls for a single, continuous 
contraction, the other for a series of separate contractions. 

A, WITH CONTINUOUS CONTRACTION 

Method. — Set the metronome at QO,i.e., so that it beats once per 
second. Adjust the dynamometer to S's hand, as in Test 6. Move 
the friction or recording pointer of the instrument well over to the 




KYMOGRAPH, IN HORIZONTAL POSITION. 



A clock-vvoi-k mechanism, with regulating fans, in the base, rotates 
the drum at constant speed and at any desired rate from one revolution 
in ten seconds to one revolution in ten minutes. Used for making graphic 
records upon smoked paper. 



right, off the face of the scale. Instruct S that he is, at the signal 
'now,' to grip as forcibly as possible, to maintain this grip with his 
utmost effort until told to stop at the end of one minute, and to keep 
his eyes fixed upon the pointer, so as to hold it as high as possilile. 
(This instruction is designed to act as an incentive to maximal exer- 



TEST 9: ENDURANCE OF GRIP 89 

tion.) Let the instrument be held in the vertical plane with the 
right-hand edge resting on the table before which S is seated. 

E starts the metronome, and, when he has caught the rhythm, 
starts the stop-watch, at the same instant saying 'now' for S to 
begin. E immediately takes the first reading, and thereafter 
glances at the scale at every fourth beat of the metronome. In the 
intervals, he records, of course, the reading of the pointer just 
obtained, estimating to the nearest half-kilogram. If the first read- 
ing is secured promptly, E will have 16 readings at the end of one 
minute. 




FIG. 16. SUPPORT FOR KYMUGKAFH DRUM WHILE BLACKENING PAPER. 

Variations of Method. — With the aid of the kymograph 
described in Test 10, E may secure a graphic record of S's work, 
either by the use of the pneumatic tambour (the Smedley instrument 
is fitted for pneumatic transmission), or by the use of a simple 
system of levers to magnify the movement of the handle.^ The 
quantitative evaluation of the resulting curve may then be obtained 
by a series of measurements of the ordinates taken at regular dis- 
tances and checked by the record obtained as prescribed, or by 



' For a cut showing the method of securing a dynamograph record, see 
MacDonald (29, p. 1184). 



90 PHYSICAL AND MOTOR CAPACITY 

ineasurenient with a planinieter of the area oncloscd by the cui've 
and its base hue. 

Treatment of Results.— (1) For some purposes, the resuhs 
may be treated by simpl}^ averaging the 16 readings, but (2) it will 
usually be more instructive also to compare the initial with the final 
stages, in order to secure an index of endurance, or conversely, of 
fatigue. For this purpose, average the first four readings and the 
last four readings; subtract the latter from the former, and divide 
the remainder by the average of the first four readings. This may 

be expressed by the formula .t = " when .r = the desired 

index in terms of per cent, n = the M of the first, and n the M of 
t\\v last readings. Or, (3) more simply, one may indicate endur- 




FIG. 17. MAREY TAMBOUR. 

For securing tracings l)y pneumatic transmission. The ruWher mem- 
brane is not shown. 

ance by the relation of the average to the maximal grip. (4) Fol- 
lowuig Binet and \'aschide (7), the records of strong, average, and 
weak N's (judged by their maximal grip) may be collated and treated 
in three groups, in order to trace the presence of the three types of 
endurance (see below) . 

R. with separate contractions 

Method. — Adjust the metronome, dynamometer handle and 
pointer as in the first method. Inform ^' that, as the word is given, 
he is to make a series of 16 grips, each as forcibly as possible, and 
that these grips will be signalled at 4-sec. intervals. E then 
signals 'now' on every fourth beat of the metronome, and takes the 
readings as previously described. 



TEST 9: endurancp: of grip 



01 



Variations of Method. — Substitute the kymograph tracing as 
suggested above. If this is done, there is no reason why the rate of 
effort may not be increased, so as to secure 60 or 120 contractions 
per minute, with a correspondingly more rapid onset of fatigue. 

If it is desired to compare results obtained with the dynamometer 
with those obtained by the common form of ergographic experi- 
ment, it is suggestetl that E repeat the experiments made upon Chi- 
cago school children. For this purpose, substitute the Mosso ergo- 
graph for the dynamometer; use the kymograph for securing the 
graphic record, and the record furnished by the endless tape, multi- 




FIG. 18. MOSSO ERGOGRAPH, MODIFIED BY LOMBARD. 



plied by the weight, for the quantitative result. Adjust the weight 
at 7 per cent of aS's weight, and time the contractions to accord with 
the beats of a metronome set at 30, so as to secure 45 lifts in 90 sec. 

Treatment of Results. — This may follow the lines already pre- 
scribed. 

Results. — (1) The measurement of endurance by the use of the 
dynamometer has been tried by Binet and Vaschide, though under 
conditions somewhat dissimilar to those we have suggested, upon a 
group of boys aged 10-13 years (6) and upon a group of young men 
aged about 18 (7). When five (or ten) grips with each hand, alter- 



92 



PHYSICAL AND MOTOR CAPACITY 



nately, were required, these authors made out four types of endurance 
curve, viz : (a) a sudden drop, then fairly constant, (6) an approxi- 
mately stationary or constant type, which is quite common, (c) a 
continuous, but gradual drop, and {d) a more or less definite rise. 
The last is rather infrequent (it was not found, e.g., by Claviere, 
in tests with 15 successive grips), but is sometimes given by vigor- 
ous individuals, though the third type is more common for such sub- 



TABLE 21 

Types of Endurance in Dynamometer Trials: kilograms {Binet and Vaschide) 





TYPE a 


TYPE 6 


TYPE C 


lYPE d 


1st Grip 

2d Grip 

3d Grip 

4th Grip 

5th Grip 


23.00 
18.45 
19.00 
18.60 
18.20 


18.70 
18.60 
19.20 
19.40 

17.80 


24.12 
22.50 
21.17 
21.33 
19.80 


17.33 
17.70 

18.67 
18.67 
20.67 



jects. Practically 90 per cent of endurance records can, in the 
judgment of these writers, be classed in one of these four categories. 
Table 21 gives average records of five grips, made with the right 
hand, by groups representing these four types of endurance curve. 
(2) If we accept this hypothesis of 'types,' it is clear that the 
dynamometer yields a more reliable indication of the comparative 



TABLE 22 
Opposed Types of Endurance, 10 Readings {Binet and Vaschide) 



NUMBER OF GRIP 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


Subject B 


36 
36 


34 
37 


34 
42 


30 
43 


29 
45 


28 
42 


25 

42 


26 
45 


26 
46 


^9 


Subject R 


45 







muscular capacity when it is employed to test endurance in this way 
than when merely a single grip is taken, as in Test 6. To take an 
extreme, though actual case cited by Binet and Vaschide, it will be 
seen (Table 22) that, if two subjects belong to opposing types, their 



TEST 9: ENDURANCE OF GRIP 93 

actual capacities may be completely unsuspected when but a single 
test is taken. 

If we turn to the use of the ergograph, we find the following 
important, though too often conflicting results. 

(3) Ergograph curves are affected by practise improvement, 
which, according to Bolton and Miller (10), results (a) from 'inure- 
ment,' i.e., a fairly rapid "process of hardening and toughening of 
the skin where it comes in contact with the apparatus and of habitu- 
ating the muscles to the strains which the unusual effort imposes," 
(6) from improved coordination in the movements concerned, par- 
ticularly seen in the disappearance of useless movements, (c) from 
improvement in the rhythmic execution of the contraction, and {d) 
from a slow increase in endurance proper, primarily in the nerve 
centers. This increase of practise, as Oseretzkowsky and Krae- 
pelin (34) have shown, affects both the height and the number of 
lifts, and gradually becomes less and less noticeable as maximal 
practise is attained. 

(4) The amount of work that can be done by the muscle is 
increased if the rate of lifting is increased from 30 to 60 or 120 lifts 
per minute (Oseretzkowsky and Kraepelin). 

(5) The work done is conditioned by the load lifted or tension of 
the spring. One can not, wdthout caution, compare ergograms 
made with different loads. 

(6) The total amount of physical work done, as measured by 
weight X distance, can not be regarded as a necessarily correct 
index of the physiological capacity of the muscle; thus, 100 lifts of 
25 mm. each may not be assumed to be physiologically equal to 50 
lifts of 50 mm. each (Binet and Henri, 4; Franz, 15). 

(7) The weight ergograph is not adapted to the measurement of 
muscular capacity (Binet and Henri, 4), hence "the fatigue curves 
obtained by Mosso and later investigators with weights do not 
represent the true state of the neuro-muscular system" (Franz, 15). 

(8) "The isotonic use of a weight or a spring for measuring mus- 
cular force is not justified, because two variable factors, extent and 
force, are introduced," so that an isometric spring (such as the dyna- 
mometer) should be used for all comparative experiments (Franz). 

(9) With improperly contrived apparatus or inexperienced sub- 
jects, the ergographic tracing is very liable to be affected by the play 



94 PHYSICAL AND MOTOR CAPACITY 

of muscles other than those under examination (Binet and Henri, 4. 
Bergstrom, 2) . Miiller (33) considers the failure properly to isolate 
the muscle a fundamental defect of the ergograph. 

(10) In addition to these specific criticisms, more general conclu- 
sions of a negative character may be quoted. Thus, Bolton (8) 
asserts that the ergograph is not adapted for measuring the degree 
of fatigue in school children; Bolton and Miller (10) conclude that 
ergograph records "have slight validity until inurement has become 
thorough and coordination complete, that the ergograph is quite 
unadapted to the obtaining of exact statistics upon a large number 
of individuals, and that records taken upon unpractised subjects, 
both before and after operations whose influences are thought to 
affect muscular power, are without the slightest claim to trust- 
worthiness." Similar conclusions are reached by Ellis and Shipe 
(14), after a retrial of the methods of Keller and of Smedley 
also by Thorndike (40) and, with some qualifications, by Berg- 
strom (2). 

(11) The effect of physical work upon ergographic curves seems 
to vary with the physical condition of the individual and with the 
nature and duration of the exercise. Thus, Bolton (8, 9) found his 
ergograms decreased by a 2-hour walk, but Oseretzkowsky and 
Kraepelin found that a 1-hour walk caused at first a transient 
improvement, then a reduction, the first of which they attribute to 
the increased excitement of central motor tracts, and the second to 
the dampening influence of general muscular fatigue. Smedley(37) 
tested Chicago children before and after a 40-minute class exercise 
in the gymnasium with the result that the stronger pupils were 
little affected, whereas weak and nervous pupils were decidedly 
exhausted. From this study he concluded that the classes in physi- 
cal culture should be graded on a physical, instead of on an intellec- 
tual basis. 

(12) Extensive study of the effect of mental work on physical 
endurance has so far yielded but discordant results. Some of this 
work, e.g., that of Keller (20), may be thrown out of court at once as 
careless in plan and execution and merely illustrative of blind infat- 
uation for the ergograph. Typical conclusions of other investiga- 
tors are as follows : Larguier (24) reports that two hours of mathe- 
matics, and Bolton that two hours of adding, definitely increase the 



TEST 9: ENDURANCE OF GRIP 95 

ergograph record; Claviere (13), on the other hand, reports that 
two hours of intense mental work produces a defmite and propor- 
tionate dimmution of muscular force, whereas intellectual work of 
medium intensity does not produce any appreciable weakening of 
endurance ; he further confesses his inability to determine the rela- 
tive fatigue-effect of various school studies. The careful ergo- 
graphic tests of Oseretzkowsky and Kraepelin show that work- 
capacity is increased after one hour of simple addition or learning 
of 12-place numerals, but that it is lessened if the mental work is 
rendered more difficult, as by adding under distraction. In an 
extensively quoted study, Kemsies (21) reports the results of a long 
series of tests upon a selected group of average, industrious boys 
who had been trained to the use of the instrument, from which he 
concludes (a) that the ergograph is a reliable indicator of true 
fatigue (lowered fund of energy as distinct from weariness) , (6) that 
subjective feelings of bodily or mental condition may not accord 
with real capacity, (c) that some of the pupils in the Berlin schools 
show, at least for the time being, signs of overwork, (d) that special 
attention should be paid to pupils who fatigue easily, (e) that one 
can determine for each study its special fatigue-value or 'ergo- 
graphic-index,' more particularly, that the several studies range 
themselves, in order from highest to lowest fatigue-index, as fol- 
lows: gymnastics, mathematics, foreign languages, religion, Ger- 
man, science and geography, history, singing and drawing. 

In the attempt to explain these divergences, Binet and Henri (4) 
suggest that we must always distinguish between mental work 
conducted without emotion and that conducted with emotion; 
they conclude that the former, if prolonged, may be expected to 
lessen endurance, the latter to produce a transient increase fol- 
lowed by a decrease. Kraepelin (23), somewhat similarly, con- 
cludes that, while hard mental work certainly reduces muscular 
energy, deviating results may appear in ergograms on account of the 
condition of excitement (Anregung) that normally accompanies 
mental work, and that may be expected to affect, either positively 
or negatively, the tracing which follows such work. Kraepelin fur- 
ther calls attention, as do Ellis and Shipe, Bergstrom, Franz, and 
others, to the very large normal variation in the curves of any indi- 
vidual, due to the operation of numerous constant and variable fac- 



96 PHYSICAL AND MOTOR CAPACITY 

tors, often little understood. Many results are valueless (e. g., in 
his opinion, those of Kemsies) because of the failure properly to 
eliminate or evaluate these factors. 

(13) The investigations of Christopher (12) and Smedley (37) at 
Chicago indicate a thorough-going correlation between endurance 
and class-standing, according to the method of percentile grading, 
the method of distribution of 12-year old pupils, and the method of 
comparison of the endurance of children at and above grade with 
that of children below grade at each age. Again, boys in the school 
for incorrigible and truant children were found to exhibit, at every 
age, less endurance (62 per cent to 82 per cent) than normal boys of 
the same age. 

( 14) The endurance of boys is greater than that of girls at all ages, 
and the difference becomes very striking during adolescence (37). 

(15) The development of endurance and that of vital capacity bear a 
decided resemblance to one another, whether pupils are examined 
singly or collectively (37) . 

(16) The diurnal 'course of power' according to the Chicago 
experiments may be expressed as follows: "(a) The extremes of 
endurance and fatigue in school are greater in the morning than in 
the afternoon; (6) a higher grade of power is found in the morning 
session in children attending two sessions daily; (c) while endurance 
is not as great, it is better sustained in the afternoon." Compila- 
tions of the ergograms of 1127 pupils place the maximum at 9 a. m. 
and the minimum at 12 noon. Kemsies considered the first two 
morning hours the best. Experiments upon adults by Lombard 
(28), Harley (16), Storey (39), and Marsh (30) exhibit considerable 
lack of agreement with one another or with the Chicago results, 
though Marsh summarizes them by the statement that the curve of 
strength efhciency seems well established for the following course : 
"& beginning minimum in early morning, a fairly rapid rise till 1 1, a 
level or slight decline till 1 p.m. ( ± 1 hour), an increase to the max- 
imum at 5 p.m. ( ± 1 hour), thence a fall till bed-time." 

(17) Kemsies concludes that Monday and Tuesday, or the first 
two days after any rest pause, are the best days for general efficiency, 
and he further concludes that vacations exert a powerful effect upon 
efficiency, but, since this effect can not be traced for longer than four 
weeks, school terms should be broken up by more frequent vacations 
of shorter duration. 



TEST 9: ENDURANCE OF GRIP 97 

(18) If ergographic contractions are continued to the point of 
exhaustion, we have both the sum total of the height of the lifts and 
their number for indexes of the neuro-muscular condition. Hoch 
and Kraepelin (18) are of the opinion that, in this case, the height of 
contraction is conditioned by the state of the muscles, but the num- 
ber of contractions by the state of the central nervous system; the 
two factors should, therefore, be reported separately for their diag- 
nostic value. On the other hand, Lombard (28) concludes that, at 
least when the contraction is not faster than once per second, the 
amount of fatigue experienced by the central nervous system does 
not correspond to the number of lifts, but rather to the strength of 
the motor impulses discharged, so that the sum total of the height 
of lifts is the more accurate index of the state of the central nervous 
mechanism. 

(19) According to Lombard, endurance is increased by exercise, 
rest (especially sleep), food, increased atmospheric pressure, and 
by small doses of alcohol, but lessened by general and local fatigue, 
hunger, lessened atmospheric pressure, high temperature, especially 
with high humidity, and by tobacco. Oseretzkowsky and Krae- 
pelin find that coffee increases the height of lifts, and that alcohol, 
in quantities from 15 to 20 g., causes at first a considerable increase, 
especially in the number of lifts, but that this soon disappears. On 
the other hand. Rivers and Webber (36) have discovered that small 
doses of alcohol (5-20 cc.) fail to produce any appreciable modifica- 
tion of the ergographic record if proper precautions are taken to 
keep the subject in ignorance as to when alcohol is administered. 
The results of previous workers are therefore presumably due to the 
influence of other factors, particularly interest and sensory stimula- 
tion, and no future work on the effects of small doses of alcohol can 
be acceptable unless these factors are controlled. 

Harley (16) concludes that ''moderate smoking, although it may 
have a slight influence in diminishing the power of doing voluntary 
muscular work, neither stops the morning rise nor, when done early 
in the evening, hinders the evening fall." 

Notes. — In either form of test, E must practise his work until it 
becomes automatic. He must take care to keep his eyes directly 
over the pointer to prevent the error of parallax in reading. For 
this reason it will be found most convenient for S and E to sit on 
opposite sides of the table. 



98 PHYSICAL AND MOTOR CAPACITY 

The stop-watch is used both to test the metronome and to check 
up the duration of the experiment, but ought to be virtually unnec- 
essary after E has practised the experiment sufficiently. 

In the first form of test, the pointer is apt to fall by a series of sud- 
den drops, or even at times to rise as *S makes a momentary recovery. 
E must take the reading precisely on the beat of the metronome, 
regardless of the position of the pointer just before or just after the 
beat. 

To hasten the acquisition of skill in conducting the second form 
of test, E will find it helpful to accent the spoken 'now' and to get 
the swing of the four-beat rhythm by mentally counting the other 
beats, thus: "Now, two, three, four: now, two, three, four." As 
soon as the utterance becomes automatic, E can give his whole 
attention to the readings and the recording of them, and an accurate 
record can be obtained from very quick and brief excursions of the 
pointer. Incidentally, some »S's may be found who are inclined to 
hold the pointer up too long : they must be cautioned against this, 
otherwise fatigue will set in very rapidly, 

REFERENCES 

(1) K. Aars and J. Larguier, L'effort musculaire et la fatigue des centres 
nerVeux, in A. P., 7: 1900 (1901), 187-205. 

(2) J. A. Bergstrom, A new type of ergograph, with a discussion of ergo- 
graphic experimentation, in A. J. P., 14: 1903, 510-540. 

(3) S. Bettmann, Ueber die Beeinflussung einfacher psychischer Vor- 
gange durch korperliche u. geistige Arbeit, in P. A., 1 : 1895, 152-208. 

(4) A. Binet and V. Henri, La fatigue intellectuelle, Paris, 1898. Pp. 336. 

(5) A. Binet and N. Vaschide, Examen critique de I'ergographe de Mosso, 
in A. P., 1897 (1898), 253-266. Also, Un nouvel ergographe, dit ergographe 
a ressort, ibid., 303-315. 

(6) A. Binet and N. Vaschide, Experiences de force musculaire et de fond 
chez les jeunes gargons, ibid., 15-63. 

(7) A. Binet and N. Vaschide, La mesure de la force musculaire chez les 
jeunes gens, ibid., 173-199. See also ibid., 236-244, 245-252, and 295-302. 

(8) T. Bolton, The reliability of certain methods for measuring the degree 
of fatigue in school children, in P. R., 7: 1900, 136-7. 

(9) T. Bolton, Ueber die Beziehungen zwischen Ermlidung, Raumsinn der 
Haut und Muskelleistung, in P. A., 4: 1902, 175-234. 

(10) T. Bolton and Eleanora Miller, On the validity of the ergograph as 
a measurer of work capacity, in Nebraska Univ. Studies, 1904, 79 + 128. 

(11) J. Cattell, An ergometer, in Science, n.s., 5: 1897, 909-910. 



TEST 9: ENDURANCE OF GRIP 99 

(12) W. Christopher, Rept. on child-study, reprint from An. Rept. Brd. 
Educ. Chicago, 1898-99. 

(13) J. Claviere, Le travail intellectuel dans ses rapports avec la force 
musculaire mesuree au dynamometre, in A. P., 7: 1900 (1901), 206-230. 

(14) A. C. Ellis and Maud Shipe, A study of the accuracy of the present 
methods of testing fatigue, in A. J. P., 14: 1903, 496-509. 

(15) S. I. Franz, On the methods of estimating the force of voluntary 
muscular contraction and on fatigue, in Amer. J. Physiol., 4: 1900, 348-372. 

(16) V. Harley, The value of sugar and the effect of smoking on muscular 
work, in J. of Physiol., 16: 1894, 97-122. 

(17) L. Hirschlaff, Zur Methode und Kritik derErgographenmessungen, 
in Z.P.P., 3: 1901, 184-198. 

(18) A. Hoch and E. Kraepelin, Ueber die Wirkung der Theebestand- 
theile auf korperliche und geistige Arbeit, in P. A., 1: 1896, 378-488. 

(19) T. Hough, Ergographic studies in neuro-muscular fatigue, in Amer. 
J. Physiol., 5: 1901, 240-266. 

(20) R. Keller, Padagogisch-psychometrische Studien, in Biol. Central- 
blatt, 14: 1894, 24-32, 38-53, 328-336. 

(21) F. Kemsies, Zur Frage der Ueberbiirdung unserer Schuljugend, in 
Deutsche med. Wochenschrift, July 2, 1896, 433. See also his Arbeits- 
hygiene der Schule auf Grund von Ermiidungsmessungen, Berlin, 1898, 
and in S. Z., 2: 1899, Heft i., Pp. 64. 

(22) E. Kraepelin, Zur Ueberburdungsfrage, Jena, 1897. Pp. 49. 

(23) E. Kraepelin, Ueber Ermiidungsmessungen, in A. G. P., 1: 1903, 
9-30. 

(24) J. Larguier, Essai de comparison sur les differentes methodes pro- 
posees pour la mesure de la fatigue intellectuelle, in A. P., 5: 1898 (1899) 
190-201. 

(25) F. S. Lee, Fatigue, in the Harvey Lectures, Phil., 1906, 169-194. 
Also in J. Amer. Med. Ass., 46: 190G 1491, and in Studies in Physiology, 
Columbia Univ., 1902-7. 

(26) E. H. Lindley, Ueber Arbeit u ; i Ruhe, in P. A., 3:1900, 482-534. 

(27) J. Loeb, Muskelthatigkeit als Mass psychischer Thatigkeit, in Arch, 
f. d. ges. Physiol., 39: 1886, 592-7. 

(28) W. F. Lombard, Some of the influences which affect the power of 
voluntary muscular contractions, in J. of Physiol., 13: 1892, 1-58. 

(29) A. MacDonald, Experimental study of school childern, etc., reprint 
of chs. 21 and 25 of U. S., 1899. 

(30) H. D. Marsh, The diurnal course of efficiency, Columbia Univ. 
diss., N. Y., 1906. Pp. 99. 

(31) A. Mosso, Fatigue, Eng. tr., N. Y., 1904. Pp. 334. 

(32) G. E. MuUer, Review of A. Waller's ",The Sense of Effort," in Z. P., 
4: 1893, 122-138. 

(33) R. Miilier, Ueber Mosso's Ergographen, etc., in Ph. S., 17: 1901, 
1-29. 

(34) A. Oseretzkowsky and E. Kraepelin, Ueber die Beeinflussung der 



100 PHYSICAL AND MOTOR CAPACITY 

Muskelleistung durch verschiedene Arbeitsbedingungen, in P. A., 3: 1901, 
587-690. 

(35) W. Rivers andE. Kraepelin, Ueber Ermiidungu. Erholung, in P. A., 
1 : 1896, 627-678. 

(36) W. Rivers, The influence of small doses of alcohol on muscular acti- 
vity, in P. B., 5: 1908, 49. See also Rivers and H. Webber, The influence of 
small doses of alcohol on the capacity for muscular work, in B. J. P., 2: 
1908, 261-280. 

(37) F. Smedley, Rept. dept. child-study and pedagogic investigation, 
reprint from 46th An. Rept. Brd. Educ, Chicago, 1899-1900. Also in U. S., 
1902, i., 1095-1115. 

(38) T. Storey, The influence of fatigue upon the speed of voluntary con- 
traction of human muscle, in Amer. J. Physiol., 8; 1903, 355. 

(39) T. Storey, (a) Some daily variations in height, weight, and strength, 
in Amer. Phys. Educ. Rev., 6: 1901. (b) Daily variation in the power of 
voluntary muscular contraction, {6i(i., 7: 1902. (c) Studies in voluntary 
muscular contraction, Stanford Univ. Press, 1904. 

(40) E. L. Thorndike, Mental fatigue, in P. R., 7: 1900, 466-482, 547-579. 

(41) W. Weygandt, Ueber den Einfluss des Arbeitswechsels auf fortlau- 
fende geistige Arbeit, in P. A., 2: 1897, 118-202. 



TEST 10 

Quickness or rate of movement : Tapping. — This has probably 
been more frequently applied than any other 'motor test,' and has 
been thought to afford a better index of motor capacity than any 
other single test. Recent work with tapping, however, while not 
discouraging the belief that the test has value, has shown that we 
cannot regard speed of voluntary movement as an unequivocal and 
comprehensive 'index of voluntary motor ability,' because a high 
gross rate does not necessarily go hand in hand with high speed in 
other phases of motor response, and because, moreover, we do not 
know precisely what may be the ultimate neural or psychophysical 
factors that condition the rate. 

Aside from its use in the attempt to secure this 'index of volun- 
tary motor ability,' the tapping test has been employed to secure an 
index of righthandedness (for which purpose it may be advanta- 
geously combined with Tests 6, 9, 11, and 12), and to secure an 
index of fatigue (likewise preferably in conjunction with other tests 
of physical capacity) . These several indexes have been studied in 
various comparative investigations, more especially in estimating 



TEST 10: TAPPING 101 

I sex and age factors in motor development and the relation of physi- 
cal to mental ability at large. 

The method has ranged from the very simple making of dots or 
vertical marks with pencil and paper (Binet and Vaschide) to the 
execution of difficult trilling movements upon telegraph keys. The 
apparatus here prescribed is somewhat elaborate, but experience 
has shown that the tapping test cannot be conducted without care- 
ful control of experimental conditions, and the use of a reliable 
recording device, such as the graphic method suppHes. 

Tests like rapid counting aloud or the rapid reading of digits or 
the reaction-time test, are not psychologically comparable to the 
tapping test. Again, the form of test used at Columbia University 
and elsewhere to measure rate of movement (making a dot as rap- 
idly as possible in each of 100 one-cm. squares) is not equivalent to 
the tapping required in most quickness tests, since a certain 




FIG. 19. TAPPING-BOARD. 

amount of precision is demanded of each movement, and that test 
therefore stands midway between Tests 10 and 11, as here pre- 
scribed. 

Materials. — Tapping board, 55 x 10 cm., with brass plates 10 
cm. square on either end (Fig. 19). Tapping stylus, with flexible 
connecting wire attached. Kymograph (Fig. 15) with accessories, — 
paper, smoking device, shellac solution. Double time-marker (Fig. 
20). Seconds' pendulum (Fig. 21) or other noiseless instrument 
arranged to give electric contacts once per sec. Support with level- 
ling screw and right-angle piece to hold time-marker. Table 
clamps for tapping board. Large sheet of gray or white card- 
board. Suitable supports and clamps for holding cardboard. 
Two short-circuiting keys (Fig. 22) , or simple knife switches. Stop- 
watch. Four dry or Leclanche cells. Flexible covered Avire with 
connector tips or ordinary No. 18 annunciator wire. [A swivel 



102 PHYSICAL AND MO TOR CAPACITY 

chair adjustable in height and an ammeter or battery-tester are also 
convenient, though not absolutely essential.] 

Preliminaries. — (1) Clamp or screw the tapping board securely 
to the side of a table in such a manner that S may have free access to 
either end of the board for using either right or left hand. Arrange 
*S's chair so that he sits sidewise to the table with his forearm rest- 
ing comfortably along the tapping board and his hand directly over 
the metallic plate. 

(2) Place the kymograph in a horizontal position, screened from 
*S's view by the sheet of cardboard. ^ Adjust the fans or gear- 




p'lG. 20. TRIPLE TIME-MARKER. 

The double and the single time-marker are of simihir construction. 

wheels so that the drum makes (for a 30-sec. test) one revolution in 
about 40 sec. 

(3) Remove the drum and cover with the prepared paper by 
simply moistening the gummed end, taking care to draw it evenly 
and tightly around the drum. Blacken the paper by revolving it 
slowly in a smoky flame.- Replace carefully in the kymograph. 

* The screen is to avoid the distraction of S's attention by the operation 
of the apparatus. If separate tables are used for tapping board and kymo- 
graph, this may not be necessary, but it is commonly more convenient to 
assemble all the apparatus on a single table. 

2 An oil stove from which the top is removed is excellent for this purpose, 
as the flame is very sooty and not so hot as the gas flame often employed. 
A simple support (Fig. 16) is used to hold thedrum. both for the smoking and 
for the subsequent removal of the paper. For this and other details in the 



TEST 10: TAPPING 103 

(4) Adjust the time-marker on the support so that the pointers 
bear upon the drum with just sufficient pressure to make a satisfac- 
tory tracing. The pointer must move in a plane parallel to the 
plane of a tangent drawn through the point of contact. 

The manipulation of the apparatus may be facilitated by fastening upon 
the table, in front of, and parallel to the surface of the drum, a straight bit 
of wood somewhat longer than the drum. Let the foot of the tripod which 
contains the levelling screw stand away from the drum, and the other two 
feet bear against the wooden strip. A half turn of the levelling screw will 
then free the pointers from the drum, and the entire support with the time- 
marker may be slid along to a new position, when another half turn of the 
screw will quickly adjust the pointers for the next record. 

(5) Wire one signal-magnet in series with the tapping board 
stylus, short-circuiting key, and two cells of the battery. The 
magnet will then be set in motion by the tapping when the key is 
closed. 

(6) Wire the second magnet in series with the pendulum, second 
short-circuiting key, and remaining two cells of the' battery. This 
magnet will then be set in motion by the pendulum when its con- 
trolling key is closed, and will thus beat off the time-line. 

Method. — (1) Seat S for the use of his right hand. Instruct 
him to tap as rapidly as possible from the signal 'now' to the signal 
'stop,' which will be given about one-half minute later. Tell him 
to pay attention only to his tapping. He may be allowed to exer- 
cise some latitude with regard to the type of movement used (short 
or wide excursion), unless he is inclined to adopt a very heavy whole- 
arm pounding movement. The most favorable movement for 
most ;S's is that obtained by resting the elbow on the tapping board 
and using both the wrist and elbow joints. 

(2) Start the seconds' pendulum and close the time-line circuit. 

use of the kymograph, consult Titchener, Experimental Psychology, vol. I, 
Part II, pp. 172-180. 

If an extended series of tests is to be made, cover the drum permanently 
with the regular kymograph paper, and, for the records, superpose two nar- 
rower strips, say 75 mmi wide. These strips are wide enough to record the 
right and left-hand efficiency of one *S : they can then be removed promptly 
for fixing, and thus the danger of injury is lessened, the ease of handling in- 
creased, and the blackening of the metal drum is less likely to be a source 
of annoyance. 



104 



PHYSICAL AND MOTOR CAPACITY 



(3) Start the kymograph, and at the same time give S the signal 
'now.' 

(4) When S is fairly started, throw in the record magnet by 
closing its key, and at the same instant start the stop-watch. 

(5) At the expiration of 30 sec, break the record circuit, signal 
'stop' to S, stop the kymograph and the watch, and open the time- 
circuit. [E must practise the whole series of operations until they 




FIG. 21. seconds' pendulum. 



run smoothly and automatically, especially the simultaneous opera- 
tion of watch and record key.] 

(6) Now adjust the pointers for a new record. Let S sit facing 
in the other direction, and test the left hand by the use of the plate 
at the other end of the tapping board, following the directions given 
for the test of the right hand. 



TEST 10: TAPPING 105 

Variations of Method. — (1) The duration of the test may be 
lengthened to 45 sec. or longer, or shortened to 10 or 20 sec. It is, 
however, desirable for the sake of comparison that a standard dura- 
tion be employed. Thirty sec. is adequate for all ordinary pur- 
poses. 

(2) It is recommended that, whenever time permits, more than 
one trial be made for each hand. To follow the procedure sug- 
gested by Wells, E should first make five trials with the right, then 
five trials with the left hand. Each trial lasts 30 sec, and is fol- 
lowed by a rest-pause of 2.5 min., during which S should refrain 
from all muscular effort. The five trials of 30 sec. each constitute 
one 'record,' and the two records of right and left hand constitute 
one 'experiment.' 




FIG. 22. SHORT-CIRCUITING KEY (dU BOIS REYMOND). 

(3) To make the test comparable to the form employed by some 
investigators, an ordinary 'sending' telegraph key may be substi- 
tuted for the tapping board and stylus. But the key has the disad- 
vantage of imposing 'a certain restriction upon the type of move- 
ment, and will be found in practise to reduce the record of many *S's. 

(4) By using the key, E may compare S's rate of tapping with 
different fingers. For this purpose, it is well to fasten clown the 
forearm with a strap at the wrist, so as to allow movement with the 
fingers only. 

(5) Again, by using the key, a trilling movement, executed by 
alternate movements of the index and middle fingers, may be sub- 
stituted for the regulation tapping movement. Without practise, 
this movement is quite difficult for some aS'.s, whereas for others. 



106 PHYSICAL AND MOTOR CAPACITY 

notably for those who have practised trilling exercises on the piano, 
it is comparatively easy.^ For this reason, this form of experiment 
is not advised, save for some exceptional purpose, e.g., testing the 
effect of practise upon the acquisition of a new bit of manual dex- 
terity. Other modifications suggest themselves, such as trilling 
with the 4th and 5th fingers — an exercise likely to be unfamiliar even 
to *S's who have 'taken lessons.' 

Treatment of Results. — (1) When the record has been made, 
use any pointed article to mark it for future identification (*S's name 
or number, date, hand used, etc.) ; then remove carefully for preser- 
vation. A simple and satisfactory method is to pour a very thin 
solution of shellac and wood alcohol, or of powdered resin (not over 
10 per cent) in alcohol, into a saucer or shallow dish, and to pass the 
strip through this, smoked side up. Hang the record up to dry, 
and pour the solution back into a wide-mouthed bottle, where it 
should be kept tightly stoppered. The record will dry in a few 
minutes and can then be trimmed and handled with impunity. 

(2) The result of the test is commonly expressed simply by the 
total number of taps executed, but it is quite as important, if not 
more important, to consider changes of speed during each trial. 
The requisite data must be secured by the rather laborious process 
of counting the strokes made by the recording-magnet upon the 
blackened paper, and tabulating them by 5-sec. intervals, as illus- 
trated below. The 'total efficiency' of a 'record' (5 trials with the 
same hand) is the average of the sum of the taps per trial. This 
serves as the gross index of speed : the rates for the 6 intervals within 
each trial afford an opportunity for studying variations in perform- 
ance. 

The use of an electric counter, such as some investigators have employed, 
would eliminate this work, but the counter gives no indication of changes 
in speed during the trial. Moreover, the electric counter is not reliable: 
even with 10 or 12 cells of battery, it will miss a quick tap which the graphic 
method will record. It follows that all results based on the use of the coun- 
ter are to be looked upon with suspicion, so that the conclusions of Bagley, 



1 The effect of piano practise, as the investigations of Binet and Courtier 
(2) and of Raif (14) show, is to improve coordination of movement, i,_ e., its 
regularity, smoothness, etc., but not to increase the natural capacity for 
speed or rate of movemeot. 



TEST 10: TAPPING 



107 



Bolton, Marsh, Kelly, Smedley, and possibly those of Bryan, Davis, Gilbert, 
and Dresslar should be accepted with reservation. 

(3) To secure an index of fatigue, E may compare the record of 
the first 5 (or 10) sec. with that of the last 5 (or 10) sec. by the use of 
the formula for determining the relative loss of efficiency given in 
Test 9. 

Wells has published extensive conclusions concerning fatigue in tapping 
that are based upon a differently computed index. The average number 
of taps executed in the 2d, 3d, 4th, 5th and 6th 5-sec. intervals are 
divided by the number of taps executed in the 1st 5-sec. interval. This 
index is somewhat misleading, in so far as a high index indicates a low 
degree of fatigue. If it is deemed worth while to relate the last five to 
the first of the six intervals to compute fatigue, it would be better, in the 
author's opinion, to subtract the average in question from the initial 
speed and divide the loss by the efficiency of the first interval. 

TABLE 23 

Sample Record of a Tapping Test (Wells) 



NUMBER OP INTERVAL IST 


2d 


3d 


4th 


5th 6th total 


1st trial 

2d trial 

3d trial 


41 


37 
37 
39 
39 
39 


35 
36 
37 
37 
38 


34 34 

35 1 34 
37 35 


32 
34 
34 


213 
217 
222 


4th trial 


40 
41 


36 
37 


36 
36 


35 
36 


223 


5th trial 


227 




40.6 


38.2 


36.6 


35.8 


35.0 34.2 


220.4 













(4) To secure an index of righthandedness, E may compute the 
percentage of the left-hand to the right-hand efficiency. The 
fatigue-index of the right hand may also be compared with that of 
the left hand in a similar manner. 

Typical Results. — Table 23 shows a sample record of the work 
of a normal adult with the right hand, when near the Hmit of prac- 
tise. The tabulation is in accordance with that recommended 
when five 30-sec. trials are made. 

General CoNCLUSiONS.^^though the tapping test is one of the 
most objective that can be apphed, and although it has been tried 
by a large number of investigators (see the references at the end of 



108 PHYSICAL AND MOTOR CAPACITY 

the test), the results have not been always accordant, and, with the 
exception of the recent work of Wells, have not been so treated as to 
afford real insight into the factors that underlie their appearance. 
The lack of accordance is to be attributed in large part to differ- 
ences in method of procedure. Differences in apparatus, too, have 
been sufficient to account for some discrepancy, as has already been 
pointed out. As regards method, the duration of the test, to 
instance a single point, has varied from 5 sec. (Binet and Vaschide, 
Bryan, Kirkpatrick) to 2 min. (Thompson), with intermediate dura- 
tions, such as 10 sec. (Bagiey), 30 sec. (Smedley), 45 sec. (Gilbert), 
60 sec. (Kelly), or the test has been conducted in 5 series of 5 sec. 
each (Bolton).^ 

In so far as these divergences of method may be neglected, we 
may note the chief conclusions of interest concerning the tapping test, 
as follows. 

(1) In general, the maximal rate of voluntary movement varies 
with the individual, with sex, with maturity, with the side of the 
body used, with practise, with the number of trials (duration of 
experiment), with fatigue, with mental excitement, with the time of 
day, but not, within wide limits, with the amplitude of the move- 
ment. ^ 

(2) Constant mdividual differences in rate of tapping can be 
demonstrated without much difficulty, but we cannot at present 
explain them, save to say that they are conditioned in a general way 
by fundamental neural factors, or by these plus differences in ability 
to coordinate voluntary movements.^J Thus, in 10 adults tested 
by Wells (10 trials for each hand), the average total efficiency (taps 
in 30 sec.) was approximately 194, but the fastest 8 averaged 225, 

' The situation here, as in most tests, shows clearly how desirable it would 
be to establish some standard form of test and to use it alone for all compar- 
ative purposes. 

^ For a fuller discussion of these conditions, consult Dresslar, Bryan, and 
Wells. 

^ To quote from Wells (19, p. 444): "What is the precise physiological 
significance of the maximum rate is by no means well made out. ... It 
seems to be generally conceded that it is limited by the refractory phase 
of the synapses in the motor pathways, but that does not make the tapping 
test a measure of the period of this refractory phase; at least, not in the 
earlier stages of practise. ... In the beginning, as we ordinarily have 
to apply the test, the factors in speed are probably those of coordination 
mainly, and cannot be expected to afford information about the condition 
of the motor pathways as given in the refractory phase." 



TEST 10: TAPPING 



109 



and the slowest 153. Since the m.v. is small (here approximately 1 
to 3 per cent) these figures undoubtedly indicate persistent char- 
acteristic differences. In general, it may be said that, for adults, 
initia l right-hand rates range from 5 to 14 taps per sec. 
ff^ (3) The rate of tapping increases with age, at least between 6 
--.and^lS^years. The slight drop at 13, upon which Gilbert comments, 
appears in Bryan's tables with some qualifications, but not so 
clearly in Smedley's results, which are reproduced herewith : it will 
be seen, however, that boys make no apparent gain from 13 to 14. 



TABLE 24 

Dependence of Rate of Tapping upon Age (Smedley) 





NUMBER 
. TESTED 


Boys 


NUMBER 
TESTED 


GlKLS 


AGE 


TAPS IN 30 SECONDS 


TAPS IN 30 SECONDS 




Rt. Hand 


Lt. Hand 


Rt. Hand 


Lt. Hand 


8 


31 
60 

47 
49 


147 
151 
161 
169 


117 
127 
132 


31 
44 

48 


146 
149 

^F>7 


117 


9 


118 


10 


129 


11 


141 48 1 169 
145 50 169 
156 45 178 
155 67 181 

169 48 : 181 

170 50 188 
174 : 40 184 
183 24 193 


139 


12 


44 ' 170 
50 184 
40 184 
37 1 191 
21 ! 196 
13 196 
3 197 


140 


13 


153 


14 


157 


15 


159 


16 


167 


17 


162 


18 


169 

















(4) Sex. The results of most investigators lead to the conclu- 
sion that boys are faster than girls, and that this sex difference 
increases with age. Bolton, however, has reported that "the girls 
are uniformly better than the boys," while Bryan found girls 
superior at 13, when they showed improvement and the boys little 
or none, — a tendency that is apparently allied to the actual crossing 
^f the curves of height and weight.) More extensive experiments 
upon adults (10 men and 10 women) by Wells (21) now indicate 
that women surpass men in tapping with the right hand in the first 
experiment, whereas elsewhere they are inferior: the sex differences 



110 PHYSICAL AND MOTOR CAPACITY 

found by this investigator are said to be "mainly in those features 
of the experiment which especially involve the affective factor 
in the subject's attitude; and they are manifestations of the greater 
responsiveness of the women to this affective element." 

(5) The index of righthandedness (per cent left-hand is of right- 
hand efficiency) was found by Wells to range from .81 to .94, aver- 
age .90, for adults, and by Smedley to vary with age in the case of 
school children, in such a manner that the average index was .82 at 
the age of 9, and .89 at the age of 18. It is evident, therefore, that 
righthandedness, so far as tapping is concerned, is more pro- 
nounced in childhood than in adult life. Wells also states (21) that 
"the right and left hands are farther apart in women," though the 
relationship is more variable in them than in men. 

(6) Righthandedness and intelligence. Smedley's conclusion 
that there exists a positive correlation between degree of righthand- 
edness and school standing, i. e., that the left-hand more nearly 
approaches the right-hand efficiency in the case of dull and back- 
ward pupils is not confirmed by the results of Bolton. 

(7) Warming-wp. In practically every continuous psycho- 
physical activity there appears a tendency to improvement due 
to what the Germans have termed Anregung. This 'warming-up' 
is a kind of momentum, not identical with practise, and its effect 
is to increase or heighten the activity, and thus to retard or even 
to obscure the appearance of indications of fatigue. In tapping, we 
observe fatigue within each 30-sec. trial, but a comparison of 
successive trials within a record will show the improvement due 
to warming-up. With 2.5 min. rest-pauses, Wells found this 
factor to be clearly present (up to the 7th trial at least) in right- 
hand records, but by no means so evident in left-hand records. 
The effect of warming-up appears to be primari y operative in 
increa ed immunity to fatigue, and is markedly augmented by 
practise, e.g., in tests continued for 20 days.| 

(8) Spurts. The curve of performance in tapping, as well as 
any psychophysical activity, is also liable to be influenced by 
short periods of increased activity, which, to continue the analogy 
of the race-track, may be termed 'spurts' (German, Antriebe). 
Thus, Wells' discovery that the first experiment usually excels the 
second in women whereas the reverse may be true in men, is re- 



TEST 10: TAPPING 111 

f erred to a special incitement of novelty (Neuigkeitsantrieb) , which 
affects the women markedly Similarly, each 'record' may be 
affected by an initial spurt (Anfangsantrieh) or by a terminal 
spurt (Schlussantrieh) . These dynamogenic factors obvious" y tend 
to obscure the real effects of fatigue. • 

(9) Fatigue and the fatigue-index, (a) As just stated, the speed 
of tapp.ng normally declines after the 1st 5-sec. interval, until it 
is approximately ^ as great in the last as in the 1st interval (Wells). 
In 45-sec. trials, the fatigue-index (loss of last 5 sec. divided by 
initial 5 sec), according to Gilbert, is highest n young children 
(24 per cent at 8 years) and declines thence irregularly to 12.7 per 
cent at the age of 15.yT:'ests by the author of fifty 8th-grade gram- 
mar-school boys reveal a fatigue-index (ratio of loss in 3d 10 sec. to 
1st 10 sec. in 30 sec. tapping) of 13.7 per cent, m.v. 4.8 per cent, 
for the right, and 15 per cent, m.v. 4.6 per cent, for the left hand. / 

(6) According to Gilbert, the fatigue-index is higher for boys 
than for girls, but boys tap faster throughout each trial, so that 
their net efficiency is higher.' 

(c) Kelly (10), who worked on a small number of children with 
a ''fatigue-counter, "found that " A"-grade pupils fatigued less than 
"C"-grade pupils; his index (the per cent of the last to the 1st 10 
sec. in a 60-sec. trial) was for the former, with the finger 87.2 per 
cent, with the arm 88.0 per cent; for the 'atter, with the finger 
77.0 per cent, with the arm 76.4 per cent. In the author's tests, 
no correlation could be discovered between fatigue-index and school 
standing. 

(d) The effect of fatigue is progressively to 'level up' individual 
differences in speed. In other words, individual differences are 
more evident in initial than in terminal intervals (Bliss, Wells). 

(e) Objective fatigue (slowing in rate) persists after practise, 
but the subjective feeling of fatigue may be eliminated thereby. 

(/) The fatigue induced by 30-sec. tapping is apparently com- 
pletely eradicated by a 3-min. rest-pause (Wells). 

' It is more re*' e to interpret this higher index of boys as an expres- 
sion of greate nthiisiasm than to follow Havelock Ellis in his in- 
ference th« pleofthe"more continuous character of woman's 
activity ' yliss Thompson (17), from comparative tests of 
adults, ' urpass women both in initial rapidity and in 
power \ other tests show that high initial speed tends 
to be \tigueloss. 

/ 



112 PHYSICAL AND MOTOR CAPACITY 

(g) The fatigue-index of right and left hands shows only slight 
correlation (Wells). The author's tests, however, show a correla- 
tion in the case of 50 boys of .33. In some persons the left hand 
is less susceptible to fatigue than is the right hand, though the re- 
verse is the rule. 

(h) The subjective experience of fatigue, as has been intimated, 
does not accord with the objective fatigue-loss.^ 

(10) Practise (a) The effect of practise is to p oduce a gradual 
improvement in speed, with, of course, occasional losses. 

(6) The rise of the curve of efficiency is not, as in most activities, 
more rapid at the beginning than elsewhere. 

(c) Maxima efficiency, when two experiments are performed 
daily, s reached, apparently, in about 20 days. 

(d) Practise affects the left hand no more than the right; con- 
sequently the index of righthandedness is unaffected by repeti- 
tion of the test. 

(e) Practise particularly increases the rate in the later trials, 
i.e. it particularly affects warming-up, yet "the true practise gain 
is one mainly in the initial efficiency of performance, as distin- 
guished from the warming-up gain, which shows itself chiefly in 
continued efficiency of performance" (Wells). 

(/) An "ntermission of 10 to 14 days has no unfavorable effect 
upon practise gains, save that the feeling of fatigue may appear 
when work is resumed. 

(11) Diurnal rhijthm. Dresslar (7) found evidence of a diurnal 
rhythm with a minimum at 8 a.m. and a maximum at 4 p.m. 
Marsh (12 also found that afternoon records generally surpas ed 
those of the morning, though his figure;, do not accord very closely 
with those of Dresslar : Marsh also discovered that the later periods 
in the evening, which were not tested by Dresslar, furnished the 
most rapid rates of all. 

1 According to Wells: "The objective fatigue phenomena which we note 
in the tcgt are in all probability either afatiguephenomenonin the refractory 
phase or a lowered efficiency of coordination, especial'- - Droduct of altered 
synaptic conditions; the sensations of fatigue, on th. 2. 'and, may with 

equal assurance be ascribed to tissue changes with- ps that take 

place as a result of their continued effort. In this t» '^e fatigue 

sensations are absolutely no indications of the a litions, 

and any traceable correspondence between fat 'atigue 

of performance must be regarded as almost whr inhi- 

bition." (19, p. 473). 



TEST 10: TAPPING 113 

(12) Dependence on 'general condition.' When general well- 
being was ranked as good, medium, below medium, and poor, 
Wells was unable to discern any relation between these several 
conditions and tapping efficiency, while there was, in the case of 
susceptibility to fatigue, a tendency, if anything toward an in- 
verse reation, i.e., fatigue seemed to be greatest on 'good' days. 
Dress' ar's observation that a vigorous walk decreases while mental 
work increases speed of tapping has been generally confirmed by 
other invest gators. 

(13) Correlation with mental ability and social status, (a) The 
correlation between tapping ability and mental ability is found 
to be generally positive by Smedley, Gilbert, Bolton, and Kirk- 
patrick, to be indifferent by Bagley (also by the author), while 
Binet and Vaschide report a positive correlation with 12-year old 
pupils and an inverse correlation with 16 to 20-year old pupils. 
While Gilbert found a very marked positive superiority of the 
'bright' children in general, the relation did not appear at ages 16 
and 17. Bolton found that "good children" (apparently meaning 
those drawn from the better social classes) were uniformly superior 
in tapping to children of the poorer class, both with the right 
and with the left hand. The fact that the divergence is greater 
at 9 than at 8 years, he attributes to a general arrest of develop- 
ment in the poorer-class children. 

(6) Bolton also states that the "good" children showed a dis- 
tinctly greater practise-improvement — a discovery which he terms 
"new and significant," and which he thinks is indicative of a fun- 
damental difference in the ability o these two classes of children 
to take on new habits and profit quickly by experience. 

(14) Abnormal types. Smith reports his inability to discern any 
characteristic differences between the speed of tapping in epi- 
leptics and in normal individuals, or between the speed of tapping' 
and the rate of involuntary tremors in these cases. Wells' study 
of several cases of retardation in the insane (20) , however, revealed 
alterations of the tapping activity, both in the form of a lowered 
average efficiency and also in the form of improvement in rate under 
conditions in which a normal individual would show either no 
changfe '6? ^ positive loss. These changes he terms 'reversal,' by 
which is r#eant intra- as distinguished from inter-trial warming- 



114 PHYSICAL AND MOTOR CAPACITY 

up, and 'transference,' by which is meant a tendency for the index 
of righthandedness to be lower when the right-hand record is 
taken after the left-hand record. 

(15) Dependence on the type of movement. The restriction of 
the tapping movement to specific joints, as has been attempted by 
some investigators, is difficult to accomplish in practise. However, 
it appears that the fastest rate is made when the movement is per- 
formed by the elbow joint, which is the one mainly concerned in 
the type of free movement here prescribed. Kelly, for instance, 
f^und that the speed of tapping was faster with the forearm than 
with the forefinger, in about the ratio 15 to 13. From this, in 
connection with other tests of dexterity, especially tests of mini- 
mal movement, he argues that children only gradually acquire 
dexterity and quickness of movement with the fingers, and that 
this passage "from fundamental to accessory," to use Burk's 
phrase, indicates the necessity of a general readjustment of the 
motor tasks required of children. 

REFERENCES 

(1) W. C. Bagley, On the correlation of mental and motor abilitj' in scliool 
children, in A. J. P., 12: 1901, 193-205. 

(2) A. Binet and J. Courtier, Recherches graphiques sur hi musique, in 
A. P., 2: 1895 (1896), 201-222. 

(3) A. Binet and N. Vaschide, (a) Epreuves de vitesse chez les jeunes gar- 
Qons. in A. P., 4: 1897 (1898), 64-98. (6) Experiences de vitesse chez les 
jeunes gens, ibid., 200-224. 

(4) C. B. Bliss, Investigations in reaction-time and attention, in Yale S., 
1: 1893, 1-55. 

(5) T. L. Bolton, The relation of motor power to intelligence, in A. J. P., 
14: 1903,615-631. 

(6) W. L. Bryan, On the development of voluntary motor ability, in A. J. 
P., 5: 1892, 123-204. 

(7) F. B. Dresslar, Some influences affecting the rate of voluntary motion, 
in A. J. P., 4: 1892, 514-527. 

(8) J. A. Gilbert, Researches on the mental and physical development of 
school children, in Yale S., 2: 1894, 40-100. 

(9) J. A. Gilbert, Researches upon school children and college students, in 
IowaS.,1: 1897,1-39. 

(10) R. L. Kelly, Psychophysical tests of normal and abnormal children; 
a comparative study, in P. R., 10: 1903, 345-372. 

(11) E. A. Kirkpatrick, Individual tests of school children, in F. R., 7: 
1900, 274^280. 



TEST 10: TAPPING 115 

(12) H. D. Marsh, The diurnal course of efficiency, Columbia Univ. diss.' 
N. Y., 1906. Pp. 99. 

(13) J. M.Moore, Studies of fatigue, in Yale S., 3: 1895,68-95. 

(14) O. Raif, Ueber Fingerfertigkeit beim Clavierspiel, in Z. P., 24: 1900. 
352. 

(15) F. Smedley, Rept. dept. child-study and pedagogic investigation, 
No. 3, 1900-1901 (Chicago Public Schools). Also in U. S., 1902, i, 1115-1138. 

(16) W. G. Smith, A comparison of some mental and physical tests in their 
application to epileptics and to normal subjects, in B. J. P., 1 : 1905, 240-260. 

(17) Helen B. Thompson, The mental traits of sex, Chicago, 1903. Pp. 
188. 

(18) F. L. Wells, A neglected measure of fatigue, in A. J. P., 19:1908, 
345-358. 

(19) F. L. Wells, Normal performance in the tapping test before and dur- 
ing practise, with special reference to fatigue phenomena, in A. J. P., 19: 
1908, 437-483. 

(20) F. L. Wells, Studies in retardation as given in the fatigue phenomena 
of the tapping test, in A. J. P., 20: 1909, 38-59. 

(21) F. L. Wells, Sex differences in the tapping test: an interpretation, 
in A. J. P., 20: 1909, 353-363. 



TEST 11 

Accuracy or precision of movement: Aiming.— ^The purposes 
for which tests of accuracy of movement have been employed 
are practically the same as those cited for the tapping test, viz: 
to obtain an index of general voluntary motor ability with which 
to compare different children to compare the right with the left 
hand, to determine the development of motor control with age, its 
differentiation with sex, and to test its correlation with mental 
ability. These tests have been only rarely used for determining 
the presence of fatigue, though they have been proposed as means 
for the diagnosis of incipient ataxia. 

Tests of accuracy vary greatly in form : in fact, they virtually 
shade by degrees from those which prescribe a rapid accurate move- 
ment similar to the tapping movement of Test 10, e.^., the Colum- 
bia test described by Wissler (5), to those which prescribe a slow 
steady movement more akin to a test for steadiness (No. 13). 

Two types of precision test have been selected for considera- 
tion, the aiming test and the line drawing or 'tracing' test ,No. 
12). 



110 PHYSICAL AND M01\>U lArAdTV 

Tho common foaturo of all forms of aimiiiii; tost is the measure- 
ment of the extent of error made by an inilividual when he tries 
in a series of discrete voluntary movements of hand or arm to hit 
some form of mark or target. According to the particular form 
of movement employed, the test has been knoMTi as the ' probing 
test,' the 'target test.' the 'thrustinii test,' etc. These movements 



+ 

1 + 

2 



3 

4 



5 + 7 

6 



8 + 10 

9 

FIG. 23. TARGET BLANK. 

The numbers are added to sliow the order in whieh the oros^ses are to be 
struek. Cut ^ size. 

have ranged, to speak more specifically, from a simple vertical prob- 
ing movement of nnn. extent (Bryan, 2) to whole-arm aiming with 
a pencil at a paper target at arm's length (Thompson, 3: Whipple, 
4), or making lunging thrusts with a wand, somewhat after the' 
fashion of a fencer, or even throwing ordinary marbles at a bull's 
eye target 2 m. distant (Bagley, l). 

The results of any such precision test will t)hviously be condi 



TEST 11: 



117 



t ioiicd by the position of the target with respect to S, by the extent 
and rate of the aiming movement, and likewise though the fact 
seems not always to have been recognized, by the individually 
variable improvement in accuracy which will appear if a series of 
' shots' are taken at the same target. Hence, to be satisfactory, an 
aiming test should prescribe and standardize all these conditions : 
it should also admit of an exact evaluation of each aiming move- 
ment/J The form of test here described was devised by the author 
severa years ago to meet these conditions and has proved satis- 
factory in use. Though the error of a single stroke is large (as 




FIG 24. AD.IUSTABLE BASE-BOARD FOR TARGET-TEST. 



is certain to be the case in any form of aiming test), the average of 
the 30 thrusts made by the same *S' is very constant. The use of 
ten marks in place of a single mark, or bull's eye, removes to a large 
extent the improvement error just mentioned. 

Apparatus. — Prepared blanks containing ten crosses irregularly 
arranged (Fig. 23). A base board upon which the blanks are 
fastened, arranged to be secured upon the wall and adjusted to 
varying heights (Fig. 24). Metronome (Fig. 14). Pencil with 
tough and moderately hard lead. M Uimeter scale. 



118 PHYSICAL AND MOTOR CAPACITY 

Preliminaries. — Fasten the board upon the wall and arrange 
the counterweight properly, so that the board will remain in any 
position from one to two meters from the floor and will not be dis- 
placed when struck by the pencil. 

Set the metronome at 69. Fasten the target-sheet upon the 
board, with the name-date corner n the lower right-hand corner 
of the board Place a demonstration target on the wall conven- 
iently near. 

Method. — Make clear to S the following directions. (1) He 
is to stand with his ight shoulder (for the right-hand test) squarely 
in front of the target, at such a distance that his pencil just strikes 
the target when his arm is fully extended.^ (2) He is to strike 
in time with the beat of the metronome. (3) Each stroke is to be 
a full, smooth stroke, not jerky or too short, and the pencil must, 
therefore, be brought back, each time, until it touches the shoulder. 
(4) He is to start at the first cross and make successive strokes, 
one at each cross in the series until the tenth is reached (see Fig. 
23). This process is twice rej^eated, but in the second round, 
further to avoid practise, the order is from ten to one. S thus 
makes three shots at each mark, or thirty in all. 

Before conducting the test proper, let S try the experiment upon 
the demonstration target. It will save time if E also illustrates 
the process at this time. E should count out the strokes of the 
metronome: 'one, two, three," etc., to assist S in getting the pro- 
per rate. 

Place a fresh sheet upon the target-board and test the left 
hand. 

Treatment of Results.- -Measure the error of each thrust by 
the application of the millimeter scale. A pair of dividers may be 
helpful in this process. Average the thirty errors and compute 
the mean variation or standard deviation. Any 'shots' that have 
struck the lines of the crosses and are difficult to detect may be 
easily located by reversing the sheet. 

Results. — (1) On the basis of similar tests, other investigators 
have shown a gradual increase in accuracy with age, particularly 
during the years 5 to 8. 

^ If the subjects are of approximately the same size, this distance may he 
marked upon the floor by a chalk line. 



TEST 12: TRACING 119 

(2) Sex differences are slight, but on the whole boys are more 
accurate than girls, and men than women. 

(3) The author, in using the test as described, has found an error 
of 4 to 6 mm. in university students, while in a group of fifty St.'ti- 
grade boys the following results were obtained : 

Right hand, average 5.12, lowest 3.75, highest 8.34. 
Left hand, average 6.39, lowest 4.15, highest 9.27. 

(4) For the 50 boys just mentioned, the correlation between right 
and left-hand efficiency was 0.54. 

REFERENCED 

(1) W. C. Bagley, On the correlation of mental and motor ability in school 
children, in A. J. P., 12: 1901, 193-205'. 

(2) W. L. Bryan, On the developvnent of vohmtary motor ability, in A. J. 
P., 5: 1892, 12:3-204. 

(3) HelenB. Thompson, The rnental traits of sex, Chicago, 1903. Pp.188. 

(4) G. M. Whipple, The influence of forced respiration on psychical and 
physical activity, in A. J. ,P., 9: 1898, 580-571. 

(5) C. Wissler, The correlation of mental and physical tests, in P. R. M. S., 
3: No. 6, 1901. Pp. 62. ' 

TEST 12 

Accuracy, precision, or steadiness of movement : -Tracing. — 

The purposes for which tracing has been used are identical with 
those outlined for the preceding test, but the present test differs 
from the former in that the movement is continuous, analogous to 
that made in drawing a line — the so-called 'writing movement' of 
Bryan (3) or 'tracing test' of Bagley (1). Since steadiness of 
movement is quite as much in demand as accuracy (of the sort 
required in Test 11), this test is often classed as a steadiness 
test, rather than as an accuracy test, but it differs from steadiness 
tests proper in that it measures control of a voluntary movement, 
whereas the latter measure the extent of involuntary movement 
which takes place when the hand or arm is held at rest (Test 13). 

The technique most commonly adopted for the tracing or line- 
drawing test consists in passing a metallic needle or stylus along a 
narrow slit between metallic strips and noting by telegraph sounder, 
bell, electric counter, or graphic record, the number of contacts 



120 



PHYSICAL AND MOTOR CAPACITY 



made in passing along a given portion of the slit. This slit may 
be straight and bounded by parallel sid(\s (Bolton, 2) or by slightly 
.converging strips (Bryan, 3; Thompson, 4), or the slit may in por- 
tions be curved, as in the scrolls used by Bagley. Some tests have 
beenvmade at Columbia University with an irregular printed pat- 
tern, wffich is to be traced by the subject with a lead pencil. In 
any of these tests, the movement may be arranged to involve pri- 
marily either the. finer muscles of the hand and fingers or the larger 
muscles concerned ir\ the whole-aun movement. 

The test here describ«ed follows the method used by Bryan and 
by Thompson. 

Apparatus. — Tracing-boarc? (Fig. 25). Metallic stylus with 
flexible connecting wire. Telegraph sounder (Fig. 26). Two 
dry or other open-circuit cells. No. 18 annunciator wire. 




FIG. 2d. rUAClNO-BOARU. 



Preliminaries. — Wire the battery in series with the tracing- 
board, the sounder, and the stylus. 




FIG. 26. telb:ghai'h sounder and key. 

The sounder may be purchased separately, l)ut the key will be found 
useful for other experimental work, if only for opening and closing the cir- 
cuit at will. When provided with a special pointer, this sounder is used for 
graphic records, as in Test 13. 



TEST 12: TRACING 121 

Method. — (1) Seat S comfortably with the tracing-board squarely 
before him, and the apex of the angle pointing toward him, 80 that 
the movement is directly toward the body in the median plane. 
Let >S hold the stylus as he chooses, place the tip at the opening 
of the strips, and then attempt to draw a line on the glass between 
the strips of metal without touching either one. The movement 
should be continuous from start to finish, made entirely free-arm 
(not a finger or wrist movement and without supporting the 
hand or arm in any way.) The rate of movement must be illus- 
trated as accurately as possible by E, and should be such that the 
full length of the strips is traversed in 9 sec. Allow S two or 
three preliminary trials, and endeavor to secure approximately 
this rate before starting the records. As soon as a click of the 
sounder indicates a contact, S is to stop and begin again with the 
left hand. Repeat until *S has made five trials with each hand, 
alternately. E records in each case the point on the scale at which 
contact is made. 

(2) Turn the apparatus around 180°, and in the same manner 
test movement away from the body. 

(3) Test movement from left to right and (4) from right to left 
with either hand, by placing the test-board so that the strips lie 
parallel with the edge of the table nearest >S'. 

Variations of Method. — (1) If it is desired not to compare 
movements in different directions, but merely to compare the 
right and left-hand efficiency of different *S's, the test may with 
advantage be shortened by adopting the method used by Bryan 
in his tests of school children, viz: set the test-board so that the 
strips make an angle of approximately 45° with the edge of the 
table, i.e., with the right-hand end of the strips turned 45° away 
from the body for the right-hand test, and with the left-hand end 
of the strips turned away to the same amount for the left-hand 
test. Make five tests with movement inward and five with move- 
ment outward with each hand. 

The conditions may be still further varied (2) by requiring S 
to stand and to hold the stylus at arm's length, (3) l)y allowing S to 
sit and to support his arm at the elbow, or (4) to support his hand on 
the base-board while executing a forearm or whole-arm movement. 
The last was the method followed by Miss Thompson. 



122 PHYSICAL AND MOTOR CAPACITY 

Treatment of Results.— The simplest treatment of the data 
is to secure an index of precision by averaging the distances 
at which the several points of contact are made. For a more 
complex method of computing the measure of precision, the reader 
is referred to Bryan, pp. 180 ff. 

Results. — (1) There is greater tariation in the outcome of pre- 
cision or steadiness of movement tests than in that of rate of 
movement tests. 

(2) There is undoubtedly a more or less constant improvement 
in precision with age, but sufficient data are not yet at hand to 
determine fhe yearly increments clearly. There is certainly, how- 
ever, a decided gain during the years 6 to 8, while Bolton also noted 
impiovement from the 8th to the 9th year of age. 

(3) Dextrality. In general, the right hand is, of course, dis- 
tinctly superior to the left, but the amount of this superiority 
varies remarkably with age, and is, according to Bryan, less evi- 
dent at 15 and 16 than at 6, 9, or 12 years of age. 

(4) Sex. With either hand, boys are probably slightly superior 
to girls, for, while Bolton reports the superiority of the girls in his 
groups of children, Bryan's examination of some 700 children re- 
vealed the following relations, when the results for both hands were 
computed together: boys were superior to girls in 51.5 per cent of 
the trials, girls superior to boys in 35.3 Der cent, and the sexes 
equal in 13.4 per cent. Moreover, in a similar test, Thompson 
found men superior to women. 

(5) Both Bolton and Thompson found movements inward or 
toward the body uniformly steadier than movements outward or 
away from the body. 

(6) Correlations. Bagley found "a decidedly inverse relation 
between mental ability, as indicated by class standings, and motor 
ability, as indicated by the tracing test." But Bolton, who used 
a different form of test, and apparently correlated rather with the 
social status than with the class standing, reports that 'good' are 
steadier than 'poor' children. 

REFERENCES 

(1) W. C. Bagley, On the correlation of mental and motor ability in 
school children, in A. J. P., 12: 1901, 193-205. 

(2) T. L. Bolton, The relation of motor power to intelligence, in A. J. P., 
14: 1903, 615-631. 



TEST 13: INVOLUNTARY MOVEMENT 123 

(3) W. L. Bryan, On the development of voluntary motor ability, in A. J. 
P., 5: 1892, 123-204. 

(4) Helen B. Thompson, The mental traits of sex, C^hicago, 1903. Pp. 
188. 

. TEST 13 

■of Steadiness of motor control: Involuntary movement. — The 

;' general idea in this type of test is to measure the amount of invol- 
untary movement which appears when the finger, hand, arm, or 
body as a whole is held as nearly motionless as possible. Like 
the preceding tests, this has been frequently employed as a means 
of obtaining an index of motor ability (Bagley, 1; Bolton, 2; 
Hancock, 6), but it has also been employed for numerous other 
purposes, e.g., for examining the motor tendencies accompanying 
ideational activity (Jastrow, 7, 8; Tucker, 15), for examining the 
bodily expression of affective states (Titchener, 14), for examining 
the nature of constant tendencies toward automatic movements, 
or the possibility of developing such movements by training 
(Thompson, 13; Solomons and Stein, 10; Stein, 12), and for 
detecting the presence of incipient or recent chorea (Crichton- 
Browne, 4). 

This variety of purpose illustrates very forcibly the difficulty 
of so conducting the test as to examine any one phase alone — a 
difficulty which is aggravated by the fact that the tracings of 
involuntary movement are often affected, not only by the factors 
implied above, but also to a considerable extent by the direciion 
of the attention, by the relative position of the body and the instru- 
ment, and by physiological processes, especially respiration. It 
is, therefore, not surprising that many writers, e.g., Bagley and 
Bolton, have incorporated records of involuntary movement only 
with qualifications and without placing much insistence on their 
worth. 

The instruments most commonly employed are the ataxiagraph 
(described by Crichton-Browne, used by him and by Hancock 
and Bolton for measuring the swaying of the body as a whole), 
the tremograph (described by Bullard and Brackett, 3, and also 
used by Hancock) for testing the arm or finger, the automatograph 
of Jastrow or that of Stein, further elaborated by Titchener, for 
measuring involuntary movements of the arm, the digitalgraph 



m 



PHYSICAL AND MOTOR CAPACITY 



devised by Delabarre (5), described, together with others of the 
instruments just named, by MacDonald (9), and used for recording 
the tremor of the j&ngejjand several instruments, as yet umiamed, 
for testing either the arm or hand, according to the conditions of 
their use.^ 

Apparatus. — Brass plate, set at an angle of 45°, and pierced with 
a series of holes whose diameters are 32, 20, 16, 13, 11, 10, 9, 8, 
and 7 sixtj^-fourths of an inch, respectively (Fig. 27). Metallic 
needle of special design, with flexible comiecting wire. Telegraph 




STEADINESS TESTER. 



sounder (Fig. 26), with writing lever attached to the armature, 
and ^vith sending key (or separate short-circuiting key) . Kymo- 
graph (Fig. 15), \vith accessories. Stop-watch (Fig. 13). Four 
dry or other open-circuit cells. Insulated connecting wire. [A 
low table, about 65 cm. high and an adjustable chair of the 
typewriter chair pattern are desirable.] 

Preliminaries. — Wire the needle, brass plate, sounder and key 
in series with the battery in such a way that contact between the 
needle and the plate will actuate the sounder. Place smoked 
paper on the kymograph drum, and adjust to approximately one 



' For some purposes it is probably quite as well to test the subject with- 
out the use of apparatus. Thus, according to Sturgis, the following consti- 
tutes an infallible test for chorea: "Bid the child liold up both hands open, 
with extended arms, the palms toward you. If that is done steadily, both 
liands ui)right and both alike, no finger or nand quivering, no falling back 
of either hancl, nothing to choose between the positions of the two, then the 
child has not, nor is it near (either before or after) St. Vitus' dance. You 
may confirm this test by another. Let ttie chila place the open hands upon 
yours, palm to palm. Look then at the backs of the child's hands, observe 
whether fingers or thumbs (.esi^ecially the latter) repose without tremor and 
without restraint." 



TEST 13: INVOLUNTARY MOVEMENT 125 

revolutioji in 40 sec. Adjust the position of the sounder so 
that the writing lever gives a satisfactory tracing on the drum.' 

Method. — Seat S before the table in a comfortable position. 
Place the brass plate flush with the front edge of the table, in front 
of aS's right shoulder for the right-hand test, and in front of his 
left shoulder for the left-hand test. Instruct S to hold the needle 
in such a way that his finger tips are in contact with the expanded 
flange of the holder, and at command, to hold the tip of the needle 
within the largest hole, and to maintain this position, so far as pos- 
sible, without touching the brass plate during the 15 sec. allowed 
for the trial. *S's hand and arm must be entirely free from all sup- 
port or contact with his body or other object, and his forearm 
should form an angle of approximately 100° with his upper arm. 
The needle should be inserted about 6 mm. into the hole. 

Show S that the click of the sounder will serve as warning for 
him that the needle is making contact with the plate. 

In conducting the test, allow *S about 3 sec. for taking the position 
(since a certain amount of movement will appear when the needle 
is first inserted that will afterward be checked by»S's control), then 
close the short-circuiting key and at the same time start the stop- 
watch. At the expiration of 15 sec, open the circuit, stop the watch 
and the kymograph, and at once rearrange the instruments for the 
left-hand test. 

Allow 30 sec. rest, and then test the right hand and the left hand 
with the next smaller hole, and so on, until a hole is reached so 
small that S has reached the limit of his capacity, and is clearly 
unable to keep the needle free from contact with the plate. 

In most cases a few unrecorded preliminary trials will show ap- 
proximately the degree of *S's control, and the tests with the larger 
holes may be omitted with a consequent saving in time. 

Variations of Method. — The test may be modified by altering 
the relative position of the plate and S's body as follows: (a) by 
requiring S to stand and to hold the needle extended at arm's 
length, (h) by allowing S to rest his elbow upon the table with the 
forearm free, or (c) by supporting his forearm and wrist and test- 
ing the steadiness of the hand and fimgers, and (d) by extending the 
time to 30 or 60 sec. The results will naturally differ character- 

' For an account of the manipulation of the kymograph, consult Test 10. 



126 PHYSICAL AND MOTOR CAPACITY 

istically from those ol)tained under the conditions prescribed as 
standard. 

Treatment of Results. — By reference to the kymograph trac- 
ings, count the number of contacts for each hole. For compara- 
tive purposes, E may take the total number of contacts made 
in a given series of holes or the number made in that hole which 
most satisfactorily tests the steadiness of the subjects under in- 
vestigation. 

Results.' — (1) In all tests of involuntary movement, it is 
clearly seen that age is an important factor. Hancock concludes 
that adults have approximately 5.8 times as much control over 
■their fingers as do children aged 5 to 7 years. 

(2) Distinct sex differences have not been established. 

Notes. — In rare cases, the use of the graphic method may be dis- 
pensed with, especially if E proves by practise very skillful in the 
correct counting of the rapid and irregular strokes made by the 
sounder when the test approaches the limit of *S's capacity, but 
this simplification is not recommended, because it is exceedingly^ 
difficult to make the count under these conditions (cf. Bolton), and 
moreover, there may appear very short rapid contacts that will 
actuate the sounder sufficiently to produce a noticeable indication 
on the tracing, but not sufficiently to produce a noticeable click. 
Again, S will occasionally make contacts of longer duration: with 
the graphic record, it is possible for E to measure the duration of 
these contacts, and, if desired, to base *S's record upon the propor- 
tion of the time during the 15 sec. that is occupied in contact, 
rather than upon the number of contacts alone. 

The electric counter is not recommended as a substitute for the 
graphic method, because, as mentioned in Test 10, it will not op- 
erate reliably when the contact is very brief, even although a large 
number of cells are used in the battery. To avoid the possibility 
of a similar error in the use of the sounder, the excursion of the arma- 
ture should be rather short, i e., the armature should be adjusted 
as near the fields as is possible if it is to give a clean stroke. 

If involuntary tremor is to be studied with special care, e.g., 
if E wishes to make an extended study of an individual case, a 

'i A summary of the results obtained with the automatograph is given by 
Lstrow (8, pp. 307-336). 



-' n. summary oi i-ne r 
Jastrow (8, pp. 307-336) 



TEST 13: INVOLUNTARY MOVEMENT 127 

more sensitive instrument should be employed. For such work, 
the tridimensional analyzer of Sommer (11), also described by 
Titchener (14), is recommended. ^^' 

REFERENCES 

(1) W. C. Bagley, On the correlation of mental and motor ability in school 
children, in A. J. P., 12: 1901, 193-205. 

(2) T. L. Bolton, The relation of motor power to intelligence, in A. J. P., 
14: 1903,615-631. 

(3).Bullard and Brackett, Boston Med. and Surg. Jour., 2: 1888, 600. 

(4) J. Crichton-Browne, The nervous system and education, being part 
4 in The book of health, edited by M. Morris, London, 1883 (now out of 
print). 

(5) E. B. Delabarre, Ueber Bewegungsempfindungen, 1891. See also A. 
P., 1: 1894 (1895), 532. 

(6) J. A. Hancock, A preliminary study of motor ability, in Pd.S., 3: 
1894, 9-29. 

(7) J. Jastrow, (a) A study of involuntary movements, in A. J. P., 4: 
1892, 398-407. (6) A further study of involuntary movement, ibid., 5 : 1892, 
223-231. 

(8) J. Jastrow, Fact and fable in psychology, Boston, 1900. Pp. 370. 

(9) A. MacDonald, Experimental study of school children, etc., chs. 21 
and 25 in U. S., 1897-8 (1899). 

(10) L. Solomons and G. Stein, Normal motor automatisms, in P. R., 3: 
1896, 492-512. 

(11) R. Sommer, Lehrbuch der psychopathologischen Untersuchungs- 
methoden, Berlin, 1899. Pp. 399. 

(12) Gertrude Stein, Cultivated motor automatisms, in P. R., 5: 1898, 
295-306. 

(13) Helen Thompson, The mental traits of sex, Chicago, 1903. Pp. 188. 

(14) E. B. Titchener, p]xperimental psychology, 2 vols., N. Y., 1901 and 
1905. 

(.15) M. A. Tucker, Comparative observations on the involuntary move- 
ments of adults and children, in A. J. P.' 8: 1897, 394-404. 



CHAPTER VI 

Tests of Setssory Capacity 

Psychophysical tests of sensoiy capacity are divisible into tests 
of liminal sensitivity (sensitivity proper) and tests of discrimina- 
tive or differential sensitivity (sensible discrimination.)^ In the 
former, we measure the bare capacity of experiencing sensations, 
the minimally perceptible stimulus or stimulus limen, e.g., the 
lightest pressure that can be felt, the least intensity of tone that 
can be heard, etc ; in the latter, we experience different sensations 
and report upon their difference; we seek, in other words, to 
determine the minimal objective difference of stimulation that can 
just be mentally cognized as different, to determine the differ- 
ence limen, e.g., the smallest change of vibration-rate that will 
suffice to yield two perceptibly different tones, or the smallest dif- 
ference in weight that can just be recognized as a difference. 

These two measurements of sensory capacity, liminal and dis- 
criminative sensitivity, can be applied to any modality, i.e., to 
any sense-department, and to any attribute of sensation, i.e., to 
quality, intensity, extent, and duration. We may measure, for 
instance, in the case of the ear, liminal sensitivity in terms of in- 
tensity, discriminative sensitivity in terms of intensity, in terms 
of quality, in terms of duration, etc. We may, furthermore, deter- 
mine the total number of auditory sensations that can be experi- 
enced, i.e., modal sensitivity. 

In the case of the two sense-departments that possess the attri- 
bute of extent, visual and cutaneous sensations, we may also meas- 
ure the capacity to discriminate difference in the localization of 
two stimuli, or the limen for spatial discrimination. While, strictly 
speaking, this may be regarded as a more complex process than 
simple sensory discrimination, it may, for our purposes, be included 

' For a discussion of the terminology, methods, purposes, and results of 
psychophysical methods, consult Titchener, E'.rpenmenfa^ Psychology, espe- 
cially, Vol. 2, part 2. 



SENSORY CAPACITY 129 

as a sensory test. Indeed, with both the eye and the skin, this 
determination, for practical purposes of exploration of the sense- 
organ or of the measurement of its functional capacity, has super- 
seded the determination of liminal sensitivity. Thus, in visual 
sensation, visual acuity refers, not to the liminal sensitivity of the 
retina for stimulation, but, in principle, to the capacity to distinguish 
tlie separation of two points. Similarly, in cutaneous sensation, 
For a practical test of functional capacity, the determination of the 
'limen of duality,' as it may be termed, by means of the esthesio- 
meter, has been more often employed than the simple determina- 
tion of liminal sensitivity to pressure. 

Now, the quantitative determination of sensitivity in the psy- 
chological laboratory has given rise to a most elaborate and re- 
fined methodology, and has, in fact, been the chief problem of the 
science of psychophysics. It is not the purpose here to discuss or 
duplicate these exact methods, but merely to indicate the maimer 
in which, for comparative purposes, one may secure an index of 
functional efficiency by empirical methods. It must be clearly 
understood that the determination of an exact stimulus or differ- 
(Mice limen in the psychological laboratory, with minute introspec- 
tive analysis of the factors that condition the process and with 
elaborate methodological procedure, is quite a different process 
from this simple determination of functional capacity for compara- 
tive purposes. If, for convenience, the technical terms of psycho- 
physics are here employed, they are employed with this qualifi- 
cation in mind. 

To make this point clearer, the procedure for the determination 
of discriminative capacity as herein reconmiended is not identical 
with any of the established psychophysical methods. E allows S 
at first to try various stimulus differences ranging from large to 
small, until *S' has acquired general familiarity with the test, and E 
has obtained a general notion of the *S's capacity. E may next test 
S more formally by applying a series of stimulus differences ranging 
from clear subjective chfference to subjective equality. Hethen 
selects a difference which seems likely to be just cognizable by the 
subject and applies this difference ten times, with proper reversals 
for time or space errors. If eight right judgments are given, he 
then corroborates the result by trying similarly a slightly smaller, 



130 SENSORY CAPACITY 

and finally a slightly larger difference, to see if S gives in the 
former case fewer, and in the latter case more correct judgments. 
S knows that a difference exists, but is ignorant of its spatial or 
temporal position.^ We thus obtain an index of capacity, but do 
not determine the mean difference limen, nor even the lower 
limen, in the psychophysical sense. 

Sensory tests of this empirical sort have been employed, partly 
in connection with the psychology of individual and sex differences, 
partly in the objective study of general intelligence, partly in the 
exploration of sense organs for the determination of their working 
condition, i.e., for hygienic and diagnostic purposes. In all of 
these fields the emphasis is upon the examination of simple func- 
tional capacity, without particular reference to introspective exami- 
nation or analysis of the accompanying consciousness. 

The use of sensory tests in correlation work is particularly interesting. In 
general, some writers are convinced that keen discrimination is a prerequi- 
site to keen intelligence, while others are equally convinced that intelligence 
is essentially conditioned by 'higher' processes, and onlj- remotely by sensory 
capacity,— barring, of course, such diminution of capacity as to interfere 
seriously with the experiencing of sensations, as in partial deafness or partial 
loss of vision. 

While it is scarcely the place here to discuss the evolutionary significance 
of discriminative sensitivity, it may be pointed out that the normal capacity 
is many times in excess of the actual demands of life, and that it is conse- 
quently difficult to understand why nature has been so prolific and generous ; 
to understand, in other words, what is the sanction for the seemingly hyper- 
trophied discriminative capacity of the human sense organs. The usual 
'teleological explanations' of our sensory life fail to account for this discrep- 
ancy. Again, the very fact of the existence of this surplus capacity seems to 
negative at the outset the notion that sensory capacity can be a condition- 
ing factor in intelligence, — with the qualification already noted. 

The tests which follow are selected from a large number of theo- 
retically possible tests, because of their i^rominence in such experi- 
mental studies as have been mentioned. Their classification is 
simply by sense-departments. Tests for the exploration of the 
organ, measurement of its defects, determination of acuity, liminal 

' Procedure with iialf-knowlodgo' in the sense used by Kampfe, in Phil. 
Stud., 8: 1893, 543, and Wundt, Grundzugc d. physiol. psvch., 5th ed., i., 1902, 
492. See also Titchener, ii, Pt. 2, 127. 



TEST 14: VISUAL ACUITY 131 

sensitivity, discriminative sensitivity, in so far as they are described, 
are given successively for each of the main sense departments. 

TEST 14 

Visual acuity. — The functional capacity of the eye is examined 
primarily, of course, for practical purposes in connection with 
hygienic investigation. Occasionally, it becomes desirable to 
determine the presence or absence of visual defect in connection 
with the administration of some mental test, e.g., the cancella- 
tion test. 

Visual acuity has been studied in its relation to school stand- 
ing, general intelligence, occupation, habitat, race, sex, as well as 
to bodily disturbances, such as headache, chorea, indigestion, or 
other optical defects, such as strabismus, total color-blindness, etc. 

Optical inefficiency, aside from color-blindness, may be due to 
amblyopia (dimness of sight not due to refractive errors or demon- 
strable lesion), or to asthenopia (general impairment of retinal effi- 
ciency due to anaemia, over-use, etc., and often yielding to proper 
medical treatment), but is more commonly some form of ametropia 
(defect in shape of the eye-ball, lens, or cornea, with resultant de- 
fect in refraction and in the formation of the retinal image). 

Ametropia may exist as presbyopia, myopia, hyperopia, or astig- 
matism. 

Presbyopia is the- long-sightedness of old age, due to the lessened elasticity 
of the lens. 

Myopia, or short-sightedness, is commonly produced by too long an eye- 
ball, the effect of which is to allow rays of light in distant vision to focus in 
front of the retina and hence to produce a blurred image when they finally 
impinge upon the retina. The myopic eye is thus unable by any effort 
clearly to see objects situated at distances of 2 m. or more away, while its 
'near-point,' i. e., the nearest point at which clear vision is possible, is 
brought correspondingly closer, so that objects may be seen clearly when 5 
or 6 cm. distant, — something which would be impossible for the normal 
(emmetropic) eye. Myopia is rarely congenital, but is an acquired defect, 
and characteristically a disease of civilization and culture. Pure myopia, as 
a rule, causes no eye-strain, but it is nevertheless a serious condition, because 
of its tendency to increase in degree, and because of the appearance in many 
cases of concomitant pathological disturbances of the retina, which, in 
extreme cases, result in actual blindness. In practise, moreover, myopia is 



182 SENSORY CAPACITY 

rarely found pure, but complicated with astigmatism and other defects. It 
may be counteracted, and its progress checked, but not cured, by the use of 
properly fitted concave lenses, supplemented by the exercise of caution in 
the use of the eyes. 

Hyperopia, hypermetropia, or long-sightedness, moi-e exactly over-sight- 
edness, is commonly produced by too short an ej^e-ball, the effect of which is 
to intercept rays of light too soon, i.e., before they are brought to a normal 
focus. The hyperopic eye must consequently exert an effort of accommo- 
dation in order clearly to see objects at a distance, while for near work 
this effort must be excessive. The result is that the hyperopic eye is under 
constant and abnormal strain from the incessant demands upon its ciliary 
muscle, and that, in consequence, numerous secondary symptoms or result- 
ant effects appear, some of them obvious, others unexpected, many of them 
serious. Local symptoms appear in inflammation, redness, or soreness of the 
eyes, lids, or conjunctiva, and in twitching and pain within the eye-ball. 
Aside from these local disturbances, perhaps the most constant symptom of 
hyperopia is frontal or occipital headache. Characteristic also is the hold- 
ing of the work at some distance from the eyes,' a peering or frowning 
expression, and dislike of near work. Eye-strain, whether hyperopic or 
astigmatic, may also occasion more serious physiological disturbances, such 
as chorea, vomiting, nervous dyspepsia, etc.- Since the hyperopic eye can 
see clearly at a distance and can read (as its possessor often boasts) with the 
book held at some distance, the defect is often unsuspected, because the sec- 
ondary symptoms are not correctly interpreted. On this account, too, it 
becomes necessary to take special steps to detect its presence, and many of 
the simple distance tests that have been applied w^holesale upon school chil- 
dren utterly fail to diagnose it. The oculist commonly makes use of hom- 
atropin or some other cycloplegic to paralyze temporarily the ciliary muscle 
and thus prevent accommodation. Hyperopia may, however, be detected, 
though less accurately, by the use of suitable test-lenses, as described below. 
The defect is counteracted by the use of properly fitted convex lenses. 

Asiigmaiism is produced by an uneven radius of curvature, usually of the 
cornea: this surface, which should normally be approximately spherical in 
form, is, in astigmatism, more strongly curved in one axis or meridian than in 
another, so that the cornea is ellipsoidal in form, e. g., like the bowl of a 
spoon, or the side, rather than the end of an egg. Thus the eye is double- 
focussed, and it is impossible by any effort to focus an image clearly in both 
meridians simultaneously. In measuring astigmatism it is evident that one 
must assign both the degree of refractive error and the axis in which the 



' In high grades of hyperopia, distinct images can not be secured even by 
this process, so the child may abandon the attempt to secure clearness and 
seek merely to increase tne size of the image by holding his book near his 
eyes. He may thus bo falsely rated as near-sighted by tlie casual observer. 

- The injurious effects of eye-strain have found a soeciai expositor in Dr. 
G. M. Goula (6, 7). 



TEST 14: VISUAL ACUITY 133 

error lies, and that in correcting it, a cylindrical lens of the proper curvature 
must be placed before the eye at exactly the proper axis to counteract the 
indicated deficiency. This lens only counteracts the defect, and does not 
cure it. Astigmatism may be in part congenital, in part a phenomenon of 
growth (often attributable to the pressure upon the eye-ball of the eye-lids 
and contracted brows, with the result that the maximal refractive index lies 
at or near the vertical meridian). When present in large amount it becomes 
a serious obstacle to vision; when present in small amounts, as is apt to be 
the case in many ej^es, it is the occasion of the same phenomena of eye-strain 
that have been mentioned as accessory to hyperopia; astigmatic headache 
is particularly symptomatic, — indeed, 60 per cent of all headaches are said 
to be traceable to this source. 

It must be understood that these three defects may, and commonly 
do, appear in combination, particularly astigmatism with hyperopia or 
myopia, and that the defects may be, and commonly are, unlike in the two 
eyes of the same individual. Partly for this reason, the proper fitting of 
glasses is an art, and, like any art, requires great skill, complete familiarity 
with the conditions, and long practical experience. The tests which are 
here described make no pretence to exactitude, but are designed to deter- 
mine, in so far as is possible by simple methods, the existence of defects that 
should invariahly he referred to a specialist for further examination and 
treatment. 

For the examination of refraction the chief appliances are (1) 
the ophthahnometer, for the exact measurement of the degree 
and axis of astigmatism, (2) the ophthalmoscope, for the examina- 
tion of the retina, (2) the retinoscope and the skiascope, for the 
objective determination of refractive errors, (4) test-types and 
trial lenses, for actual visual tests under varying conditions. While 
retinoscopy is a method of great value, especially in testing young 
children, the test-type is, in general, the court of final appeal and 
constitutes the most widely used and perhaps the most valuable 
single means for testing visual acuity. The most varied kinds of 
test-type have been devised by oculists. Perhaps oldest and best 
known are Snellen's "Optotypi," which form the basis of the tests 
ordinarily used. Interesting variations are seen in Dennett's 
Monoyer type, Landolt's C-test, and Cohn's E-test. 

The simple test which is described just below is recommended 
by the American Ophthalmological Society, and is designed to be 
used in connection with Dennett's type, with the employment of 
but two test lenses. The second test supplements the first by 
detecting astigmatism. Tests 15, 16, and 17 may be added. 



134 SENSORY CAPACITY 



A. TEST FOR AMETROPIA 



Apparatus.- — Dennett's Monoyer test-type (Fig. 28).^ Trial 
frame (Fig. 29). Two — .75 D. and two + -75 D. spherical lenses, 
and one blank disc. 



MRTVruENCXOZD 

dlvatB KuehSn 
nCTHOFMErSPA 

EXAtZHDWN 

Y E I K S F D I 

X P H B Z D 

N L T A V R 

H S UE 

M C F 

Z u 

Fi(?. 28. Dennett's monoyer test-type. 

About T natural size. The small figures that indicate the normal distance 
for each line are not shown. 

' Other test-types may, of course, be employed. Landolt's or Snellen E- 
test (designed for illiterates) are recommended, if Dennett's is not used. 
Landolt's type is placed at 5 m., Snellen's at 6 m. Visual acuity is indicated 
in the latter by a fraction in which the numerator is 20 (feet) and the denom- 
inator is the number (in feet) indicated for the smallest line that can be read 
at the standard distance of 20 feet. 



TEST 14: VISUAL ACUITY 



135 



Preliminaries. — Place the test type on the wall or stand, on a 
level with S's eyes, in a strong even illumination, though not in 
actual sun-light.^ Seat S comfortably at a distance of 6 m. from 
the chart. 

Note any indication of soreness or inflammation of the eyes, lids, 
or conjunctiva. Ascertain if S has ever suffered from such inflam- 
mations, from habitual headaches, or watery eyes ; whether his eyes 
l)ecome painful, sore, or strained in doing close work; whether he 




FIG. 29. TRIAL FRAME. 

Holds two pairs of lenses, and has rack and pinion adjustment for pupil- 
lary distance, and for vertical, and back and forward movement of the nose- 
piece. 

has previously been examined, and if so, with what result; whether 
he has ever worn glasses; if they have been worn and discarded 



' If conditions render daylight illumination unreliable or unsatisfactory, 
E must arrange artificial illumination, carefully shaded from *S. Excel- 
lent devices for this purpose may be purchased from dealers in optical sup- 
plies, e.g., No. 4274, catalog of E. B. Meyrowitz, New York City, price SIO. 
Whatever the source of illumination, the light must not shine in *S"s eyes. 

An experienced £ may compensate for inadequate illumination by plac- 
ing <S at a distance less than 5 m.,— the amount of the correction being deter- 
mined by ^'s own acuity under the prevailing conditions. 



136 SENSORY CAPACITY 

ascertain when and why. If S wears glasses, record that fact ; test 
his vision both with and without his glasses, unless time forbids, in 
which case test with them. 

Adjust the pupillary distance and the nose-piece of the trial frame 
so that the lenses will be centered l^efore S's eyes. 

Method. — (1) Place the solid disc in the frame before »S's 
left eye. Instruct him always to keep both eyes open. Ask him 
to read the top or smallest line. If this line can be read entire, or 
at least 11 of the 13 letters can be read, record the vision of the 
right eye as 1. (indicated by the figure at the right of the line), 
thus, V. R. E. = 1. If he sees nothing clearly above, say the 
4:th line, l)ut can read that correctly, then record, as indicated 
on the chart, V. R. E. = .7. If *S camiot read any of the lines, 
record V. R. E. = — .7, which is practically blindness. 

(2) Whatever the result of this first trial, always next place the 
+ .75 D. lens in the trial frame. This will blur the vision if the eye 
is emmetropic, so that, if before, V. R. E. = 1., and if vision is now 
blurred, record V. R. E. = 1. Em. 

If >S can, with the plus lens, read the same line as before, or a 
smaller line than before, then the eye is hyperopic. Thus, if pre- 
viously the 4th line was read and now the 2d, the record will be, 
V. R. E. = .7 + Hy. = .9, or, if no improvement appeared, V. R. E. 

= .7 -f- Hy. = .7. 

(3) If, in the first test, vision is less than 1.0, and if, in thesecond 
test, vision is impaired by the convex lens, then next replace the con- 
vex lens by the — .75 D. lens. If vision is now improved so that a 
smaller line is read, say the second or the first, then the eye is 
myopic, and may be recorded thus; V. R. E. = .7 -|- My. = .9, or 
V. R. E. = .7 + My. = l.i 

(4) Place the solid disk before the right eye, and test the left 
eye similarly. Record the results for each eye separately, e.g., 
V. R. E. = 1. Em. V. L. E. = .6 + My. = .9. 

' This test may be nullified in some instances bj- a ciliary spasm in a hyper- 
opic eye which may simulate myopia of almost any degree. 



TEST 14: VISUAL ACUITY 
B. TEST FOR ASTIGMATISM 



13/ 



Apparatus. — Trial frame and lenses as above. Verhoeff's astig- 
matic chart (Fig. 30). ^ 

Preliminaries. — Place the chart on the wall, and seat S as in the 
previous test. Be sure that S's head is held squarely erect, [f S 




30. VERHOEFP" S .ASTIGMATIC CHART. 

About I natural .size. 



has been found to be myopic or hyperopic, place in the trial frame 
the lenses which correct, at least partially, this defect. 

Method. — Place the sohd disk in the frame before the left eye. 
Ask S whether one or more of the radiating lines seem to him sharper 
and blacker than those at right angles to them. If he answers in 
the affirmative, astigmatism is present. This result may be con- 
firmed by causing S to move his head from one shoulder to the 
other, in which case the location of the sharpest lines should shift 
in a corresponding manner. The degree of astigmatism may be 

' Any standard astigmatic cnarx, maj- be substituted, but Verhoeff's isj 
in the author's judgment, best adapted both for making evident the presence 
of a.stigmatism and for determining approximately its axis. 



138 SENSORY CAPACITY 

roughly judged by the positiveness and readiness of *S's answer; its 
axis may be determined approximately by his designation of the 
blackest line or lines. 

Place the disc before the right, and test similarly the left eye. 

Since astigmatism may exist either alone or in combination with 
some form of ametropia, it should, when found, be recorded with 
the previous determination, e.g., V. R. E. = .7 + My. = .9 + As. 

If vision is less than .7, but no form of ametropia can be demon- 
strated, the defect is recorded as amblyopia, e.g., V. L. E. = .6 + 
Am. 

To summarize the two tests: emmetropia is indicated (unless 
strain symptoms point to concealed hyperopia) by the reading of 
the smallest line and subsequent blurring by the convex lens, hyper- 
opia by improvement or lack of impairment of vision by the plus 
lens, myopia by vision less than 1 ., which is improved by the concave 
lens, astigmatism by unequal clearness of the radiating lines, 
amblyopia by vision less than .7 without demonstrable refractive 
error. 

Results.' — (1) The frequency of defective visual acuity is 
somewhat difficult to state accurately owing to the differences in 
method and in degree of rigor and precision that have characterized 
the many investigations upon this point. In especial, a great many 
investigations in school systems have been made by simple distance 
tests without the aid of lenses, so that hyperopia, the most frequent 
defect, has gone practically unmeasured. The general outcome of 
these simple tests is quite uniform, viz: that one child in three in 
the public schools suffers from visual defect. Typical figures are 
those obtained by Welch (20) at Passaic, and Smedley (15) at Chi- 
cago; the lattqr reports that 32 per cent of the 2030 boys and 37 per 
cent of the 2735 girls examined were defective in vision. While 
more than half of these defects are of a minor degree, yet, as already 
indicated, these may be productive of immediate distress and entail 
serious consequences if neglected. 

' For a general discussion of the examination of eyesight, with special 
reference to the eyesight of school children, consult Barry (1) Calhoun (3), 
Carter (4), Cohn (5), Gould (6,7), Hope and Browne (8), Kotelmann (9), 
Newsholme (10), Risley (12,13), Schmidt-Rimpler (14), Snell (16), Stilling 
(17) and Young (21). 



TEST 14: VISUAL ACUITY 139 

On the other hand, examinations that have been conducted by 
skilled opthalmologists with some refinement of method indicate a 
much larger percentage of defect.^ Risley's figures indicate that 
it would be more correct to state that seven children in eight, than 
that one in three, are ametropic. As chairman of the Philadelphia 
committee that examined some 2500 children, he gives the refrac- 
tion at 8| years of age as hyperopic in 88.11 per cent of cases, 
emmetropic in 7.01 per cent, and myopic in 4.27 per cent: at 17.5 
years as hyperopic in 66.84 per cent, emmetropic in 12.28 per cent 
and myopic in 19.33 per cent. 

(2) From the above figures we may conclude that the eye in 
early childhood is an incomplete eye, naturally underfocussed and 
poorly adapted for near work. But, as general bodily maturity 
approaches, the eye under optimal conditions tends to become 
emmetropic. Conditions of modern life, however, are not optimal 
for the eye, but rather encourage overuse and neglect, with the con- 
sequence that these, especially when added to astigmatism or other 
congenital defects, produce eye-strain, myopia, and other disturb- 
ances of vision. 

(3) Cohn, especially, has demonstrated that myopia is essen- 
tially a disease of civihzation and culture; that it is infrequent in 
peasants and those who lead an outdoor life, and progressively more 
prevalent and of higher degree as persistent study and near work 
continue. Thus, in gymnasia, he found that the percentage of 
myopia increased during six years of study in the following manner : 
12.5, 18.2, 23.7, 31.0, 41.3, 55.8. Similarly, of 138 pupils at the 
Friedrich gymnasium who were examined twice at an interval of 18 
months, he found at the first test 70 normal and 54 myopic, whereas 
in the second test, 14 of the 70 had become myopic, 28 of the original 
myopes had developed a higher degree, and in 10 per cent, serious 
structural changes had taken place in the retina.^ 

Indeed, there are specialists who assert that an absolutely perfect pair 
of eyes does not exist. 

- Diirr, in explanation of the alarming prevalence of myopia in Germany 
as contrasted with other countries, has sought to show its dependence upon 
the excessive demands of theGerman schoolsystem : he estimates that, during 
the years 10 to 19, the typical English boy spends in study 16,500 hours, in 
exercise 4500; the French boy, in stud> 19,000, in exercise 1300; and the Ger- 
man boy, in study 20,000, and in exercise 650. These statistics showing the 
relation between myopia and excessive near work could be multiplied almost 
indefinitely. 



140 SENSORY CAPACITY 

(4) Smedley, on the basis of his method of correlation by grades, 
asserts that ''a smaller per cent of the pupils at and above grade 
have defective sight than those below grade." 

(5) Smedley further demonstrates that defective vision is 
extremely common in backward and troublesome children, and that 
this fact may be a partial explanation of the behavior of such chil- 
dren. Thus, according to the tests employed at Chicago, 48 per 
cent of the boys of the John Worthy School were subnormal in vis- 
ual acuity, as contrasted with 28 per cent of the boys of the same 
average age in other schools. Moreover, "many of the John 
Worthy boys had strabismus, hypermetropia, and astigmatism, 
concUtions which would induce asthenopia when the eyes were used 
in close and long application to books, and it is easy to believe," 
adds Smedley, "that the strain thus set up when an attempt was 
made to study was a factor in producing cUslike for school and 
subsequent truancy." 

(6) Van Biervliet (19) has sought to obtain a correlation be- 
tween the visual acuity test and intelligence, not by cUrect reference 
to visual acuity itself, but to the mean variation measured by a series 
of tests of acuity, i.e., to what he teims the capacity of attention. In 
brief, the method was to compute a fraction, of which the denomina- 
tor represented the average distance at which the test was visible, 
and the numerator the mean variation of the several trials. As 
measured by this arbitrary index, the 10 brightest and the 10 dullest 
of 300 university students were related, in terms of a common 
denominator, as 19/1000 and 62.5/1000. Binet (2), however, 
points out that the dull students had the better eyesight, i.e., the 
larger denominator, and suggests that the index be taken directly 
Prom the mean variation. 

(7) Right-euedness. While both eyes are employed for binocu- 
lar vision, there is some evidence that most persons 'favor' one 
eye, whenever, for any reason, binocular vision is not in use, e.g., 
in looking through a microscope or telescope. Van Biervliet 
(18) has measured the visual acuity of 100 persons, whose optical 
defects had previously been corrected, with the result that the 
favored eye very uniformly excels the unfavored one in visual 
acuity by one-ninth: he further asserts that right-handed people 
are right-eyed and left-handed people left-eyed, and that the same 



TEST 14: VISUAL ACUITY 141 

sort of sensorial asymmetry can be demonstrated in audition, 
cutaneous discrimination, and discrimination of lifted weights. 

Notes. — Statistics of visual defect are rendered difficult of com- 
parison, not only by differences in the methods followed in the 
investigations, but also at times by failure to state whether exam- 
inations were made with or without the glasses actually worn by 
pupils, or, in case such statement is made, to indicate the effect upon 
the results of including or excluding trials made with these glasses. 
Cohn distinguishes between visual capacity proper (Sehleistung) 
and visual acuity (Sehschdrfe) , which is the efficiency when proper 
glasses are used. But since numbers of children are daily wearing 
improperly fitted glasses, one almost needs another term to indicate 
the vision that is had with these glasses. 

The focal strength of lenses was formerly indicated in the English, 
or inch system, but it is now more common among opticians to make 
use of the metric system, in which one dioptric (D) represents a lens 
whose focal distance is one meter, 2 D. a lens twice as strong, i.e., 
with a focal distance of 50 cm., etc. 

REFERENCES 

(1) W. F. Barr\-, The hygiene of the schoolroom, N. Y., 2d ed., 1904. Pp. 
191. 

(2) A. Binet, A propos de la mesure de I'inteUigence, in A. P., 11: 1904 
(1905), 69-82. 

(3) A. M. Calhoun, Effects of student life upon eyesight. Bureau Educ, 
Washington, 1881. Pp. 29. 

(4) R. B. Carter, Report on vision of children attending elementary 
schools in London, London, 1896. Pp. 16. 

(5) H. Cohn, (a) The hygiene of the eye, Eng. tr., London, 1886. (6) 
Die Sehleistung von 50,000 Breslauer Schulkindern, nebst Anleitung zur 
ahnlicher Untersuchungen fur Aerzte u. Lehrer, Breslau,. 1899.- Pp. 148. 
(c) Was haben die.Augenarzte fiir die Schulhygiene geleistet und was miis- 
sen sie noch leisten?, Berlin, 1904. Pp. 35. (Contains bibliography of 74 
titles.) 

(6) G. M. Gould, The cause, nature and consequences of eyestrain, in 
Pop. Sci. Mo., 67: 1905, 738-747. 

(7) G. M. Gould, Biographic clinics, 5 vols., Phil., 1903-7. 

(8) E. Hope and E. Browne, A manual of school hygiene, Cambridge, Eng. , 
1904. Pp. 207. 

" (9) L. Kotelmann, School hygiene, Eng. tr., Syracuse, 1899. Pp. 382. 
(10) A. Newsholme, School hygiene, Boston, 1894. Pp. 140. 



142 SENSORY CAPACITY 

(11) Rept. com. on statistics of defective sight and hearing of public school 
children, in U. S., 1902, ii., 2143-2155. 

(12) S. D. Risley, Weak eyes in the public schools of Philadelphia: rept. 
com. on examination of the eyes of the children in the public schools of Phil., 
in Phil. Med. Times, 11 : 1880-1, 673-685. 

(13) S. D. Risley, School hygiene, being pp. 353-418 in vol. 2 of W. Norris 
and C. Oliver, System of diseases of the eye, Phil., 1897. 

(14) Schmidt-Rimpler, Die Schulkurzsichtigkeit u. ihre Bekampfung, 
Leipzig, 1890. 

(15) F. W. Smedley, Rept. dept. child-study and pedag. investigation, in 
46th An. Rept. Brd. Educ, Chicago, 1899-1900. Also in U. S., 1902, i., 1095- 
1115. 

(16) S. Snell, Eyesight and school life, Bristol, Eng., 1895. Pp. 70. 

(17) Stilling, Die Kurzsichtigkeit, ihre Entstehung und ,Bedeutung, in 
Abh. aus d. Gebiete d. padag. Psych, u. Physiol. 7: No. 3, Berlin, 1903. 

(18) J. van Biervliet, L'asymetrie sensorielle, in Bull. Acad. Royale dos 
Sciences, etc., de Belgiques, 34: Serie 3: 1897, 326-366. 

(19) J. van Biervliet, La mesure de I'intelligence, in Jour, de psj^ch., 1: 
1904, 225-235. 

(20) G. T. Welch, Report on the examination of the eyes of the public 
school children of Passaic, N. J., April, 1896. Also summarized in Ref. 11. 

(21) A. G. Young, 7th An. Rept. State Brd. Health Maine. Augusta, 
1892. Pp. 399. See especially 128-131. 

TEST 15 

Balance and control of eye-muscles: Heterophoria. — Strictly 
speaking, the examination of the condition of tlie eye-muscles is a 
physiological test, but because this condition affects clearness of 
vision, it may be included here with other visual tests. 

Each eye-ball is supplied with six muscles. By their action in 
varying combination, the eye is moved freely in its bed, somewhat 
after the fashion of a ball-and-socket joint. Under normal condi- 
tions, the balance and the iimervation of these muscles are such 
that both eyes move in concert, i.e., the eye-movements are auto- 
matically coordinated for purposes of single vision and the lines of 
regard are restricted to movements where a common fixation point 
is possible. In some individuals, however, there exists more or less 
'imbalance', or asymmetry of eye-movement, so that the two eyes 
fail to 'track,' as it were.* 

If we consider only the relations of the visual lines to one another 
and neglect paralytic affections of the muscles, we may distinguish 



TEST 15: HETEROPHORIA 143 

between latent tendencies toward asymmetry, or heterophoria, and 
actual or manifest asymmetry, heterotropia or strabismus. Follow- 
ing the terminology of Stevens (1), we may define the possibilities 
as follows: orthophoria is a tending of the visual lines in parallelism 
when the determination is made for a point not less than 6 m. dis- 
tant; heterophoria is a tending of these lines in some other way 
under the same conditions. Heterophoria may appear (a) as 
esophoria, a tending of the lines inward or toward one another, (6) 
as exophoria, a tending of the lines outward or away from one 
another, (c) as hyperphoria, a tending of the right or of the left vis- 
ual .line in a direction above its fellow,^ or (d) as tendencies in 
obhque directions, viz : hyperesophoria and hyperexophoria. 

The tendencies just described are tendencies only, and are latent 
or concealed in the ordinary use of the eyes on account of the strong 
'desire' for binocular vision. For their discovery, accordingly, 
it is necessary to resort to means for eliminating, so far as possible, 
this reflex or automatic correction of the latent tendency. The 
means most commonly employed, as illustrated in the tests that 
follow, is the establishment of disparate images on the two retinas. - 

When binocular vision is not habitually attained, the ten- 
dencies above described are no longer latent, but manifest, and 
heterotropia (strabismus or squint) is the result. Heterotropia 
may appear as esotropia, converging strabismus, or deviation of 
the visual lines inward; as exotropia, diverging strabismus, or 
deviation outward; as hypertropia, strabismus sursumvergens or 
deorsumvergens; or as compound deviations, termed by Stevens 
hyperesotropia and hyperexotropia. 

The most obvious immediate result of heterotropia is diplopia or double 
vision, a very annoying, but not usually a permanent symptom, because the 
person thus affected soon comes to neglect the bothersome image from the 
'squinting' eye, and to take account only of that from the 'fixing' eye. In 
time, there results, usually, a limitation of the movements and of the retinal 

1 The term does not imply that the line which is too high is at fault, but 
merely that it is higher. Hence, of course, the lack of necessity for any term 
to indicate that one line is lower than the other. 

2 This assumption that voluntary attempts at fusion will be renounced if 
the two images are sufficiently disparate, is not entirely correct, and in so far, 
it is not always possible to make an accurate determination of heterophoria, 
particularly when slight, by means of the principle of diplopia. Slight 
heterophoria, moreover, is not to be regarded as abnormal. 



144 SENSORY CAPACITY 

sensitivity of the squinting eye (exanopsic amblyopia), which is one of tho 
most interesting instances of the loss of function through disuse.^ 

Strabismus or heterophoria is functionally associated with ametropia; in 
particular, divergent displacement is more apt to be associated with myopia, 
and convergent displacement with hyperopia, probably as a consequence of 
the straining after clear vision under the hyperopic handicap. 

The chief instruments for the detection of muscular asymmetries 
are prisms of varying construction, the Macldox rod, and the sten- 
opaic lens. Stevens' phorometer is a device for holding and rotat- 
ing prisms with accuracy and under optimal conditions. The 
phoro-optometer is a combination of the phorometer with other 
instruments, such as the Maddox rod, Risley's prism, etc. 

Two tests are here detailed, the Maddox rod and the prism test. 
Both are convenient, portable, and inexpensive, but possess the dis- 
advantage common to all tests for heterophoria held close to the eye, 
viz : tliat *S does not always completely renounce the fusion-impulse. 

In the Maddox test, the so-called ' rod' transforms for one eye 
the flame of a candle into a long narrow streak of red light, while 
the other eye sees the candle flame naturally. Heterophoria is 
indicated by the lack of coincidence in these two images. 

The prism test, which is essentially an auxiliary test, consists 
in producing artificial displacement of images by means of the 
prisms, and measuring *S's ability to produce voluntary fusion of 
these displaced images. 

A. THE MADDOX ROD TEST 

Apparatus. — Maddox multiple red rod (Fig. 31). Trial frame 
(Fig. 29), Candle. [A set of trial prisms may be added.] 

Preliminaries. — Place the lighted candle on a level with aS"s 
eyes and 6 m. distance. Adjust the trial frame. 

Method. — (1) Let S close his left eye: place the Maddox rod 
in the frame before the right eye with the bars set horizontally. 
S should then perceive a long, narrow, vertical streak of red light. 
Then let S open his left eye and at once state whether the red 
.streak passes exactly through the candle flame. 

' As this is particularly to be feared in tne case of children, whose eyes 
liave not reacned functional maturity, prompt medical attention to strabis- 
mus is highly imperative. 



TEST 15: HETEROPHORIA 



145 



(2) Turn the rod until the bars run vertically. S will see a hori- 
zontal red streak. Let him open his left eye and at once state 
whether the streak passes exactly through the candle flame. 

Results. — In the first test, the possible results are: (a) the 
line passes through the flame, orthophoria (Fig. 32), (6) the line 
passes to the right of the flame, esophoria or homonymous displace- 
ment (Fig. 33), (c) the line passes to the left of the flame, exophoria 
or crossed displacement (Fig. 34). 




FIG. ;31. MAUDOX MULTIPLE UOD. 



In the second test, the possible results are: {(i) tlie line passes 
through the flame, orthophoria (Fig. 35), (/>) the line passes below 
the flame, right hyperphoria (Fig. 36), (c) the line passes above 
the flame, left hyperphoria (Fig. 37). 

Notes. — Next to orthophoria, esophoria is the most common 
condition. Unequal vertical adjustment, hyperphoria, is not com- 
mon, save that an upward deviation of the squinting eye is almost 
always associated with high degrees of convergent strabismus. 

If the latent asymmetry is but slight, there may appear a more 
or less rapid corrective movement: S will then notice lack of 
coincidence of the line and the flame when the left eye is opened, 
but the two images soon fuse together. On the other hand, if the 
asymmetry is larger, E may determine its degree by placing prisms 
before the left eye and ascertaining by trial how strong a prism is 
needed to enable fusion to occur. 

If both horizontal and vertical imbalance is observed, the de- 
fect is hyperesophoria or hyperexophoria. This may be demon- 
strated, if desired, by placing the Maddox rod in an oblique position. 










KIGS. 82-34. ILLCSTIIATIXG ORTHOPHORIA, ESOPHORIA, AND EXOPHORIA, 
RESPECTIVELV. 

As rovoaloii by tho ?*I:uldo\- rod when used before the right eye for hori- 
zontnl deviation. (W- Solnveit.itz i\nd Randall). 




I'Ui. OO. MADDOX TEST 
FOR VERTICAL DEVIA- 
TION: ORTHOPHORIA. 



Hi. 3t.l. MADDOX TEST 
FOR VERTICAL DEVIA- 
TION; RIGHT HYPER- 
PHORIA. 



FIG. 37. MADDOX TEST 
FOR VERTICAL DEVIA- 
TION) LEFT HTPBR- 
PHORIA. 



TEST 15: HETEROPHORIA 147 

Stevens's stenopaic lens (Fig. 38) may be substituted for the 
Maddox rod. A single determination then suffices for both hor- 
izontal and vertical displacement. In orthophoria, the candle 
Hame appears in the center of a dilTused disc of light; in hetero- 




VIG. 3S. STEVENS' STENOPAIC LENS. 



phoria, it is displaced to the right or left, above or below, or obli- 
quely, in a manner corresponding to that of the Maddox line-and- 
fiame test (Fig. 39). The stenopaic lens consists of a convex lens 




FIG. 39. HETEROPHORIA, AS REVEALED BY THE STEVENS LENS. 

of 13 D., covered, save for a very small opening in the center. 
The principle is again that of disparate images. 

H. TEST WITH PRISMS 

-Vpparatus. — Trial frame. One 2-degree, one 8-degree, and two 
20-degree prisms, of the circular pattern for the trial frame.^ Candle. 

' These prisms permit E to test S's ability to overcome the degrees of dis- 
placement that are considered standard for the three positions: their cost is 
about $4. For $10, however, a fairly complete set of prisms may be pur- 
chased, which will permit a more flexible test. 



148 SENSORY CAPACITY 

Preliminaries. — Place the lighted candle on a level with »S's 
eyes and 6 m. distant. Adjust the trial frame. 

Method.— (1) To test abduction, or /S's ability to overcome a 
standard amount of displacement by rotating the eyes outward, 
place the 8-degree prism before one eye with the base in, i.e., to- 
ward the nose. 

(2) To test S's ability in adduction, or forcible convergence, 
place a 20-degree prism, with the base out, before each eije.^ 

(3) To test >S's ability in sursumduction (compensation for ver- 
tical displacement), place the 2-degree prism, with the ])ase either 
up or down, before one eye. 

Results. — With orthophoria, S should secure fusion under the 
conditions imposed, if not at the first trial, at least after a few trials 
on different days. Failure to accomplish this, or ability to over- 
come larger angular displacements than those cited, is indicative 
of heterophoria, or of other inequalities in the set of the eye-balls, 
e.g., declination. - 

Notes. — This test may, of course, be applied to cases in which 
either orthophoria or heterophoria is present. It may be of value 
in measuring »S's control of his eye-muscles, not only as a matter of 
optical hygiene, but also in conjunction with tests and experiments 
of a psychological nature, e.g., stereoscopy, binocular fusion, and 
visual space-perception in general. 

REFERENCES 

(1) G. T. Stevens, A treatise on the motor apparatus of the eyes, Phil., 
1906. Pp. 496. 

(2) W. N. Suter, The refraction and motility of the eye, Phil., 1903. Pp. 
390. 

TEST 16 

Color-blindness.^ — This test continues the examination of the 
functional efficiency of the eye as a sense-organ. It has obvious 
practical import, as well as high theoretical significance in connec- 
tion with the theory of vision. 

' The ability to overcome prisms by convergence is about 50 degrees, 
according to Stevens, but an exact standard cannot be stated. 

2 For further details of this, and otner forms of prism test, consult Suter 
and Stevens. 



TEST 16: COLOR-BLINDNE8S 149 

The retina of the normal eye is not equally sensitive to color 
stimuli in all portions. On the contrary, simple experiment^ will 
demonstrate the existence of three distinct zones : an inner, efficient 
zone, over which we see all colors ; a middle zone, over which we see 
only blues, yellows, blacks, whites, and grays, and an outer, to- 
tally color-blind zone, over which we see nothing but blacks, 
whites, and grays. 

Color-blindness may be regarded as an arrest of development, or 
in some cases as a pathological modification, of these normal zones. 

The description and classification of forms of color-blindness has 
been much obscured, if not even actually retarded, by confusion 
in nomenclature, especially seen in the adoption of terms based on 
unwarranted, preconceived theoretical notions as to the nature 
of color vision. 

If we follow the clue afforded by the distribution of color sen- 
sitivity on the normal retina, we should expect to encounter total 
color-blindness, or partial color-blindness of a red-green type. 
Blue-yellow blindness would seem theoretically unjustifiable, at 
least as an arrest of development. And in fact we do find that all 
recorded cases of so-called blue-yellow (or violet) blindness are of 
doubtful characteT, and at least pathological in nature. 

Total color-blindness is well authenticated, but rare. Here, 
too, the defect is pathological, and is accompanied by a reduction 
in visual acuity, by nystagmus, and other serious disorders of 
the visual organ. 

We are left, therefore, with red-green blindness as the typical 
and characteristic form of color deficiency. As revealed in tests, 
this defect consists in the inability correctly to distinguish certain 
tones, particularly unsaturated tones, of red and green. The 
colors thus affected are invariably in pairs, i.e., the individual who 
fails to perceive correctly a given green will also fail to perceive 
correctly its complementary red, and conversely. 

In actual vision, certain reds and certain greens appear neutral or 
gray, 2 while tones in which red and green are conjoined with 

1 For details, consult Titchener [\2, Part I., Section 9). 

' The green which appears as gray is a somewhat bluish green, lying 
between the 6-line and the F-line of the spectrum, and having a wave length 
between 500 /i /i and 490j«/i: the complementary red is a non-spectral pur- 
plish red. 



150 SENSORY CAPACITY 

blue or yellow are seen as bluish or yellowish. The spectrum is 
thus divided into a long- waved yellow and a short-waved blue 
section. By dint of daily experience, however, the color-blind 
individual develops a capacity to recognize some reds and greens 
by means of secondary criteria, such as brightness (tint) and satur- 
ation (chroma), and familiarity with the application of color 
nomenclature (grass is green, cranberries red, etc.), so that the 
defect may exist unrecognized, either by himself or by his acquaint- 
ances, until chance compels the recognition or discrimination of 
tones to which these criteria can not be applied. Hence arises the 
necessity, in the administration of tests, of displaying a large number 
of colors of varied saturation and brightness, in order that, for 
any individual, some combination or series of combinations of 
colors may be found, in the recognition of which these criteria can 
not be used. Here, too, appears in part the explanation of the 
seeming individuality of the defect. 

Despite, and quite apart from, this variability, however, two 
very definite sub-types of red-green blinds may be distinguished, 
though the distinction is of theoretical rather than of practical 
significance : (a) those who locate the brightest part of the spec- 
trum, as do normal persons, in the yellow, and (5) those who locate 
the brightest part of the spectrum in the yellow-green region of the 
spectrum. For the latter, the entire blue end of the spectrum 
appears relatively brighter than to the normal eye. This type is 
relatively infrequent. Individuals who belong to the former type 
are called by von Kries (13) deuteranopes, and are erroneously 
called by many writers green-blinds: those who belcfhg to the lat- 
ter type are called by von Kries protanopes, and erroneously red- 
blinds. 

This confusing, if not erroneous, terminology is to be referred 
to the Helmholtz theory of color vision, wherein the three primary 
visual and retinal elements are assumed to be red, green, and vio- 
let. In theory, on this basis, it is evident that an eye might pos- 
sess all three, or but two, or but one, of these visual elements; 
that, in other words, an eye might possess trichromate,dich'romate 
or monochromate vision. Ordinary red-green blindness would, 
therefore, on this theory, be a form of dichromasy with the defi- 
ciency actually due to loss either of the red or of the green element. 



TEST 16: COLOR-BLINDNESS 151 

This terminology ignores the fact that color-blindness invari- 
ably goes in pairs/ but the terminology persists and is current in 
nearly all popular discussions of the topic. 

This forms one of the most conspicuous instances of the imposition of theo- 
retical convictions upon the interpretation, and even upon the observation of 
facts. Not a few discussions of color-blindness that make pretence to scien- 
tific aacuracy exhibit this error, and, one may add, other errors of a more 
inexcusable sort. The reader may consult, for instances, a book by Abney 
(1), which embodies his Tyndall lectures of 1894, and a magazine article by 
Ayers (2). In Abney there will be found a colored frontispiece, taken from 
the Report of the British Association Committee on Color Vision in 1892, 
which purports to show the spectrum as seen by the color-blind. The spec- 
trum is shown in green and blue: what becomes of yellow is not explained. 
In Ayers's article there will be found some very pretty colored pictures of 
roses and Venetian scenes as observed by the color-blind, — pictures that are 
good examples of the illustrator's art, but absolutely false examples of color 
vision. Mrs. C. L. Franklin (6) has charitably applied the term "pseudo- 
scientific" to such writing. A more nearly correct representation of the 
spectrum seen by the color-blind is given by Thomson (11). 

Holmgren contrasted total color-blindness with partial color- 
blindness, and divided the latter into complete partial color-blind- 
ness and incomplete partial color-blindness (confusions with the 
green, but not with the red, test skein). This division has not 
been often used, but the term 'color-weakness' has been extensively 
employed in place of Holmgren's incomplete partial color-blind- 
ness, though not quite correctly, because this group, as determined 
by the Holmgren test, may embrace both von Kries's deuteranopes 
and the so-called color-weak. 

The most recent and authoritative study of color weakness has 
been conducted by Nagel (9). According to his investigations, 
the color-weak, with the rarest exceptions, are (in Helmholtzian 
terminology, after Konig) anomalous trichromates, i.e., they pos- 
sess all the elements of color vision, but exhibit certain anomalies, 
of which the following are most prominent: (a) a considerable 
reduction of sensitivity and discriminative capacity in the region 
of yellow-green and green, (6) inability to recognize colors, particu- 
larly red and green, when of reduced intensity, small area, or brief 

1 There have been reported a few exceptions to this rule, which are diffi- 
cult of explanation by any theory of color-vision. 



152 SENSORY CAPACITY 

exposure, (c) rapid retinal fatigue to colored stimuli, (d) slow recog- 
nition of color tones, amounting, for reds and greens, to 20-50 fold 
the normal time, (e) increased dependence upon brightness differ- 
ences, (/) very marked augmentation of simultaneous and succes- 
sive contrast.^ 

Nagel suggests a further subdivision of anomalous trichromasy into pro" 
tanomalous trichr6masy (a lessened excitability to red corresponding to 
protanopia) and deuteranomalous trichromasy (corresponding to deutera- 
nopia). But, as he points out, this distinction may be somewhat premature, 
since the facts are not yet clearly established, and since a case has recently 
been discovered in which anomalous trichromasy and dichromasy appear 
to coexist in the same eye. 

In theory, the color-weak are not to be identified with the color- 
blind. Their defect ranges all the way from forms which are to be 
distinguished from normal vision only by careful tests to forms 
which closely approximate true dichromasy or color-blindness. 
PV)r practical purposes, however, they must be identified with the 
color-blind, because they are incapable of making those color dis- 
criminations that the conditions of railway and marine service 
demand. 

It is, perhaps, true that some disasters may be traceable to this defect in 
color vision, which has escaped the detection of medical examiners who have 
used only the standard wool tests. Thus, in Germany, among 1778 members 
of railway regiments, all of whom had passed the wool test and many of 
whom had also passed Stilling's test, 13 dichromates and 31 anomalous 
trichromates of various types were discovered by the use of Nagel's test 
in the hands of military physicians. Baird, however, contends that 
statistics of railway accidents show no trace of this factor. 

Color-blindness may be binocular or monocular. The latter is rare, but 
naturally of great theoretical importance in determining the nature of color- 
blindness. 

Color-blindness is usually congenital, and then incurable. The common 
form, red-green blindness, is to be regarded as an arrest of development, a 
reduction from normal trichromasy, or reversion to a more primitive form 
of retina. All acquired cases, variously attributed to traumatism, neuritis, 
atrophy of the optic nejve, hysteria, excessive fatigue, over-indulgence in 
tobacco, are accompanied by lessened visual acuity, are pathological, and 
of relatively small concern to the theory of color-vision.^ 

' For an excellent discussion of color weakness and the use of testa, the 
reader is advised to consult J. Rosmanit (10). 

^ For illustrative cases, consult Collin and Nagel (4). 



TEST 16: COLOR-.RLINDNESS 153 

Color-blindness seems to have been first noted An literature in 1684, but 
first described accurately by Dalton, the celebrated JRnglish chemist, in 
1794. The first attempt at a systematic examination of a J.arge number of 
cases was made by Seebeck in Berlin in 1837 by the aid of colbred papers. 
The first systematic examination of railway employees dates from Ib'Jo, when 
a serious accident in Sweden led Holmgren of the University of Upsaik'.to 
devise his well-known wool test and to inducp officials to adopt it.' 

The chief devices and methods for testing color-blindness are 
Holmgren's, Galton's, Thomson's, Oliver's, and other assortments 
of colored worsteds, Stilling's pseudo-isochromatic charts, Nagel's 
card test, spectroscopic examination, various contrast tests, and 
the use of equations of mixed colors, particularly Nagel's equation- 
apparatus, and Bering's apparatus,^ which enables the examiner 
to adjust a color equation of transmitted light that shall appear to 
the color-blind as uniform gray. Nagel's or Hering's apparatus 
is to be recommended for careful psychological tests. In addition, 
numerous forms of color-blindness lantern (Williams', Frieden- 
berg's, Oliver's, etc.) have been devised for testing railroad and 
marine employees by simulating the conditions of night-signalling, 
and soiled signal-flags have been used for similar purposes, while 
Henmon has proposed a discrimination-time test. 

Two forms of test are here described: the familiar and widely 
used Holmgren wool test, adopted by the American Ophthalmo- 
logical Society, and Nagel's new card test, which has now been 
specially revised for the diagnosis of color-weakness and of other 
variant types of defect. Both of these tests are inexpensive, com- 
pact, and portable. They may be employed in conjunction with 
one another. 

A. THE HOLMGREN WOOL TEST 

Material. — Holmgren's worsteds. Sheet of light gray or white 
cardboard or a similarly colored cloth. 

Method.— (a) Full procedure. (1) Remove the three large 
test skeins, pale green, red and rose, Nos. 101, 102, 103. Scatter 
the remaining skeins over the cloth or paper in diffuse daylight 

' For other details of the history of color-blindness as well as a discussion 
of methods, though not brought down to date, consult Jennings (8) and 
Thomson (II). 

= See Titchener (12. Pt. II, p. 7). 



154 SENSC/ilY CAPACITY 

only,^ Hand to S tbie green test skein, No. 101, and direct him 
to pick from the ^able all those skeins that resemble the test skein 
i.e., all the tixiits and shades of that color. Explain that there are 
no two ^specimens alike, and that an exact match is not required. 
It "^vVill do no harm to illustrate the process by selecting two or three 
skeins for him, provided these are afterward mixed with the pile. 
To save time in explanation, other *S's may be allowed to watch 
this demonstration. 

(2) If hesitation appears, or if grays, browns or reds as well as 
greens are selected, continue the test by use of the rose skein. No. 
102. The typical color-blind will then select some blues or pur- 
ples, or, less often, grays or greens. 

(3) Finally, the red test skein. No. 103, may be used, though 
many red-green blinds have little difficulty with this test on ac- 
count of the strong saturation of the test skein. 

In all three tests, preserve a careful record of the skeins selected 
by <S's who deviate in any particular from the normal. 

(6) Abbreviated procedure. This test may be used for quick pre- 
liminary examination. Place irregularly on the cloth four green 
skeins {e.g., 5, 17, 19, 49) and eight 'confusion' skeins of gray, 
brown, and pink (e.g. 8, 12, 27, 40, 44, 46, 54, 60). Hand to S 
the pale green standard. No. 101, and require him to pick from 
the cloth as rapidly as possible four skeins that match the test 
skein (in the sense previously described). Allow him approxi- 
mately 4 sec. to make this selection. If this test can not be 
promptly and accurately executed, examine S further by the full 
procedure. 

Typical Results. — (1) About 4 per cent, of men and less than 
0.5 per cent of women^ are color-blind: the most common defect is 
red-green blindness of the form known as deuteranopia. 

(2) The following are actual selections of a typical red-green 
blind. By assembling these skeins E can gain the best idea of the 
nature of the confusions likely to be discovered. 

1 When not in use the skeins must be kept carefully enclosed in their 
box, as they will fade or change color if continuously exposed to light. 

* Recent tests by Dr. S. P. Hayes seem to indicate that the frequency of 
color defect in women is much greater than this. 



TEST 16: COLOR-BLINDNESS 155 

Green standard: 5, 8, 10, 12, 13, 19, 32, 38, 45, 47, 53,60, A,C, 
D, K, N. (Occasionally some pink, like 27, is also selected.) 

Rose standard: 22 to 28, 30, 71, 72, 74, 76, 78, 79, 80, 82, 84, 
86, 88, 90, 91, 92, 93. 

Red standard: 21, 29, 31, 33, 35, 37, 39, 73, 75, 77, 85, 87, 89. 

Notes. — Inability to name colors rightly has sometimes been 
erroneously mistaken for color-blindness, but the term must 'be 
applied only to instances of actual inability to see colors rightly. 
Consequently, no color-blindness test should hinge upon the ability 
to name correctly the various colors presented, and, in the conduct 
of the Holmgren test at least, reference to color names should be 
avoided if possible. 

If ^S works very slowly and hesitatingly, but finally makes a 
correct selection, this may indicate several possibilities, which 
should be tested by further study of the case, (o) The slowness 
may be due merely to extreme cautiousness on his part, coupled 
with some anxiety or uneasiness about the test, or with failure to 
understand clearly just what is wanted. (6) The slowness may be 
due, in the case of very young children or untutored adults, to gross 
ignorance of, and unfamiliarity with colors, (c) The slowness 
may be indicative of color-weakness, in which case Nagel's test 
should be applied for further diagnosis of the defect. 

All instances in which specific color differences are at first recog- 
nized with difficulty or not at all, but in which, after coaching or 
instruction, an efl&ciency is developed adequate for passing the 
test in use, must be looked upon with suspicion, and it must not 
be assumed forthwith that color-blindness has been cured by train- 
ing, for either the cautiousness or ignorance just mentioned were 
present at first and removed by the training, or the conditions of 
the test were too simple, and secondary criteria were developed 
by,S. 

If apparent cases of blue-yellow, or of total color-blindness are 
discovered, these should, if possible, be given most careful exami- 
nation by an expert psychologist. 

It is obvious that many callings are, or should be, closed to the 
color-blind, e.g., railroading, marine and naval service, medicine, 
chemical analysis, painting and decorating, certain branches of 
botany, microscopy, mineralogy, the handling of dry goods, mil- 



156 SENSORY CAPACITY 

linery, etc. In some phases of school work, the eolor-bUnd pupil 
is likeAvise at an evident disadvantage. The test should, accord- 
ingly, be regularly instituted in the early years of school life, in order 
that the existence of the defect may be made known to the child 
as soon as possible. 

B. THE NAGEL CARD TEST 

Material. — Nagel's color-blindness cards. 4th edition.^ 
Main Test, Part I. 

Method. — Si)read out the cards of Section A upon a table, in 
chance arrangement and in good daylight illumination. These 
must be observed by .S from a distance of 7-5 cm., never less. 

(1) Ask *S to point out a card upon which red or reddish spots 
are seen (do not suggest bluish red or rose). Ask for a second and 
a third such card. 

Normal and color-weak N's will answer correctly; color-blind *S's 
will usually select a card that contains yi^low-green antl no red, 
e.g., No. 6 or 11. 

(2) Ask *S to point tmt a car(,l that contains red spots only. 
Normal ^"s answer correctly; color-weak .S's usually answer 

correctly, but may select a red and gray card; color-blind .S's fre- 
quently select No. 12, i.e., yellow-green and yellow-brown. 

(3) Ask *S to point out cards that contain (a) green spots only, 
and (6) gray spots only. 

Normal S's will select No. 5 (for green) and No. 9 (for gray), but 
No. 16 may be allowed. Normal »S's may at first also select cards 
which contain combinations of gray and green, such as Nos. 4, 
13, 14, Init will reject these after more careful examination. Color- 
weak ^"s will more often select these last mentioned cards and not 
correct the mistake. The color-blind are helpless, and can select 
the correct cards only by nu^-e chance. 

' Nagel's tost can not bo purcliasod bj' tho goneral public in the open mar- 
ket, but may be imported for use by physicians, psychologists, and biolo- 
gists, or for institutions represented by such specialists. Importation can 
be arranged through C. H. Stoelting Co., N. Green St., Chicago. 



TEST 16: COLOR-BLINDNESS 157 

Main Test, Part II. 

The object is to extend the previous test and to give more care- 
ful attention to possible cases of anomalous trichromasy. 

Method. — Display the first three cards of Section B (Bl, B2, 
B3) at a distance of 30 cm. 

(4) Point out Card Bl (green and bro\\Ti) and ask .S: "What 
colors do you see here?" 

Normal *S's will at once note the presence of two colors, though 
they may not name them correctly as green and brown, but may use 
such terms as dark yellow, gray, yellowish. Color-weak aS's may 
answer similarly, but with less certainty, and freciuently call all 
the spots green or all brown, or use the terms green and red. Col- 
or-blind ;S's call all the spots red, yellow, brown, or green, and fre- 
quently call special attention to differences in brightness of the spots.' 

(5) Point out Card B2 or B3 (red and brown) and again ask >*^ . 
"What colors do you see here?" 

Normal »S's answer correctly, though they may call the brown, 
dark-yellow. (If hesitation appears over this brown, E may in- 
(luire whether the color might be yellow, or gray, or green, or brown.) 
Color- weak »S's call this card red and green (or greenish or olive). 
Color-blind »S"s answer as in (4). 

Supplementary Test A 

This is designed for testing all difficult or obscure cases (unin- 
telligent or dull ;S"s, color-weaks, etc.) that have not given clear 
results by the preceding tests. It should be administered to all 
»S"s that have shown hesitation in the preceding trials, particularly 
when green was under test. 

Method.^ — (6) Display the cards of Section A. Ask *S to point 
out all the cards upon which red or reddish spots are seen. 

(7) Ask similarly for all cards on which green spots are seen. 

(8) Ask what cards contain no green spots. 

(9) Display Cards Bl and B2; SLsk S to point out the red and 
green spots with a pencil. 

If Tests 6-9 are answered correctly, »S is certainly not color- 
blind. 



158 SENSORY CAPACITY 

(10) If doubt remains as to whether S is color-weak, display in 
rapid succession several cards from Section A, and insert in the 
series the four cards of Section B. Ask S to state upon which 
cards green spots are found. If S mentions B2 or B3, he is color- 
weak, i.e., an anomalous trichromate. 

Supplementartj Test B 

This is designed for the special diagnosis of protanopia aiid deu- 
teranopia for scientific and statistical purposes. 

Method. — (11) Display Card B4, and direct *S's attention to the 
pairs of spots indicated by asterisks. Ask S which spot in each 
pair is darker. , If the green is selected, 8 is 'green-blind' or deuter- 
anopic, i.e., the relative brightness is approximately that of nor- 
mal vision: if red is selected, 8 is 'red-blind,' or protanopic. Red- 
anomalous and green- anomalous types may be similarly differen- 
tiated. Red-blinds wifl also find the red spots decidedly darker 
than the brown on Card B3. 

(12) Very rare cases of blue-yellow blindness may be recognized 
by inability to distinguish the blue-green from the yellow-green 
spots on Card A6 and by the designation of all the spots on B2 as red. 

Notes. — To use Nagel's test successfully, it is imperative that 
the following cautions be observed. (1) The directions for con- 
ducting the main tests must be strictly followed before attempting 
any supplementary or variant tests. (2) E must adopt a quiet, 
sympathetic manner, free from any sign of irritation or impatience, 
especially when dealing with slow or stupid >S's, or even with those 
who are plainly attempting deceit. (3) During the test, E must 
carefully avoid informing 8, whether directly or by suggestion, 
of any mistakes he may make. Discussion or criticism of *S's 
selections is out of place. For the sake of future tests, it would 
be desirable not to explain >S's errors to him even after the test. 

To avoid the effect of possible collusions between *S and previous 
*S's, Tests 4 and 5 may be preceded by similar questions applied 
to several cards taken from Section A. 

If 8 has decidedly low visual acuity, this must be corrected, at 
least approximately, by appropriate lenses, before the color-blind- 
ness test is begun. 



TEST 17: DISCRIMINATION OF BRIGHTNESS 159 

REFERENCES 

(1) W. Abney, Color vision, London, 1895. 

(2) E. Ayers, Color-blindness, with special reference to art and artists. 
In the Century Mag., 73: 1907, 876-889. 

(3) J. W. Baird, The problems of color-blindness, in P. B., 5 : 1908, 294-300. 

(4) Collin and W. Nagel, Erworbene Tritanopie, in Zeits. f . Sinnesphysiol. 
1 1 : 1906, 74-88. 

(5j Dalton, Extraordinary facts relating to the vision of colors, in Trans. 
of the Lit. and Philos. Soc. of Manchester, 1794. 

(6) Mrs..C. L. Franklin, Magazine Science, in Science, n.s. 25: 1907, 746. 

(7) V. Hennion, The detection of color-blindness, in Jour. Phil. Psy. and 
Sci. Method, 3: 1906, 341-4. 

(8) J. E. Jennings, Color-vision and color-blindness, Phil., 1896. Pp.111. 

(9) W. ]^iagel, (o) Fortgesetzte Untersuchungen zur Symptomatologie u. 
Diagnostik der angeborenon Storungen des Farbensinns, in Zeits. f. Sinnes- 
physiol., 41: 1906,239-282,319-337. (b) Zur Nomenclatur der Farbensinn- 
storungen, ibid., 42: 1907, 65. (Consult also other articles by the same 
writer in this periodical.) 

(10) J. Rosmanit, Zur Farbensinnpriifung im Eisenbahn- und Marine- 
dienste, Vienna and Leipzig, 1907. Pp. 59. 

(11) W. Thomson, Detection of color-blindness, being pp. 315-352 in 
Norris and Oliver, System of diseases of the eye, vol. ii., Phil., 1897. 

(12) E. B. Titchener, Experimental psychology, vol. i., N. Y., 1901. 

(13) J. von Kries, Ueber Farbensysteme, in Z. P., 13: 1897, 241-324. 
(Corrective note, p. 473.) 

TEST 17 

Discrimination of brightness. — The object of this, test is to 
obtain an index, for comparative -purposes, of >S's ability to dis- 
tinguish very small differences in brightness, or more exactly, to 
determine the smallest difference in brightness that >S can distin- 
guish under simple experimental conditions. The present test 
onits consideration of chromatic stimuli, and is confined to the 
discrinnnation of brightness, first by the use of reflected, sec- 
ondly by the use of transmitted light. 

Visual discrimination has been studied in the laboratory by many 
competent investigators, e.g., Anient, Aubert, Bouguer, Helm- 
holtz, Frobes, Kraepelin, Masson, Merkel, Schirmer, Volkmann, 
and others. Tests of school children by Gilbert (3) and Spearman 
(6) have followed simpler methods. 

In the laboratory, use has been made of Masson's disk, both by 
daylight and artificial illumination, of the episkotister, oi gray 



160 



SENSORY CAPACITY 



papers and of shadows. Toulouse (9) proposes solutions of ani- 
line colors in glass receptacles. Gilbert used a scries of ten pieces 
of cloth soaked in a red dye of graded intensity. Investigations 
that are most comparable with the method here proposed are those 
of Anient (1), Frobes (2), and Spearman, all of whom made use 
of gray papers, and of Gilbert, who examined school children, 
though Avith chromatic stimuli. 

A. DISCRIMINATION OF GRAYS -REFLECTED LIGHT 

Apparatus. — Set of 10 test-cards, each composed of two gray 
strips, 13 X 40 mm., on a white background, 10 x 10 cm. Exposure 
frame, fitted with a card-holder which may be rotates 1 through 




FK;. 40. AIM'AHATUS FOKTHK DISCKIMINATiOX OF UllAVS. 

180°, and with a black screen, through an opening (8x8 cm.) in 
which the test-cards may be viewed (Fig. 40). Light gray cloth. 
about 70 X 160 cm., for a background. Two supports, with angle- 
pieces, and a horizontal rod 70 cm. long. Headrest. 

The cards are numbered from to 0, corresponding to 10 different pair;? of 
.stimuli. Each card contains one strip of the lightest or standard gray, and 
one strip of comparison gray. Card No. represents no difference, or ob- 
jective equality; Card No. 1 represents the minimal objective difference; 
Card No. 9 the maximal objectiye difference and is easily supraliminal for 
the normal eye. Each card is numbered on the back in such a way that, when 
looking at the face of the card with the number up, the right strip is the 
darker; there is also a small black mark on the extreme edge of the card on 
the side of the darker strip. 



TEST 17: DISCRIMINATION OF BRIGHTNESS 161 

The grays used on these cards have been specially prepared, under the 
author's direction, by S. L. Sheldon, photographer, of Ithaca, N. Y., and 
have been carefully standardized. Each set of grays is printed from the 
same negative, on which the original series was formed by graded serial 
exposures before a sheet of milk glass set in a north window. They will not 
fade or change their tone, unless brought into contact with chemical fumes 
or solutions; but, for additional protection, they should be kept under cover 
when not in use, and never be handled in bright sunlight. 

The tones, sizes, and spatial relations of the strips, cards, and background 
have been selected to eliminate errors that might arise from adaptation and 
contrast. The size of the strips is slightly smaller than that used by Ament 
(18 X 45 mm.) and slightly larger than that prescribed by Titchener (10 x 40 
mm.) for the demonstration of Weber's law in brightnesses. 

Preliminaries. — Place a small table, say 65 x 90 cm., squarely 
before a window where good diffuse daylight may be secured (pre- 
ferably a north window with full clear exposure to the sky) ; leave 
just enough space between the front of the table and the window 
for two chairs for S and E. Spread the gray cloth over the top 
of the table, and stretch it up vertically at the back edge by means 
of the supports, so as to form a continuous background of gray, 
with the vertical back at least 65 cm. high and about 65 cm. dis- 
tant from )S's eyes. 

Place the exposure frame in the center of the table at the opti- 
mal reading distance (about 35 cm., unless S has uncorrected my- 
opia or hyperopia), and adjust it's height so that the top of the 
frame is on a level with S's eyes. Adjust the headrest so that S 
may sit erect, squarely before the exposure frame and close to the 
table-edge, with his back, of course, to the window. 

Keep the test-cards conveniently near, but out of *S's sight. 
E will find it most convenient to sit at S's right. 

Method. — (1) Spend 5 min. in giving S practise and familiar- 
ity with the test. For this purpose, begin with the large-numbered 
cards, and pass in general toward the smaller numbers, but with- 
out following any rigorous order. With each card, rotate the turn- 
table, so that the right strip is now the darker, now the lighter: 
follow an irregular order, and keep S always in ignorance of the 
actual location of the darker strip, and of the correctness of his 
judgments. In each trial, S must report his judgment in terms 
of the right-hand strip, saying either "darker," "lighter," or "equal.' 
(Any doubtful cases may be classed as equal.) 



162 SENSORY CAPACITY 

When not observing a test-card, S should rest his eyes by 
directing them toward the gray background. He turns his eyes 
to the test-card at E's ''now," and should be asked to pass a judg- 
ment within 5 sec. It is not necessary to record results at this 
point, but from this practise work, S will attain a general familiar- 
ity with the test, and E will form a fair idea of >S's ' critical' region. 

(2) Proceed now, more formally and exactly, to determine ;S's 
difference limen by selecting a stimulus difference which has 
appeared in the preliminary series to be just noticeable for him. 
Give this stimulus-card 10 times, 5 times with the right strip darker, 
5 times with the right strip lighter, but in chance order. ^ Inform 
»S that he will be shown the same card 10 times, but in different 
positions, of which he is to be ignorant. He may answer " 1 ighter," 
" darker," or "equal." (Equal j udgments may be classed aswrong.) 
S must not be informed during the series whether his judgments 
are right or wrong. If S gives 8 right answers in 10, the magni- 
tude of the brightness difference then in use affords the desired 
index. 

(3) Confirm the result by testing *S 10 times with a slightly 
larger difference, and 10 times with a slightly smaller difference. 
Unless the tests are disturbed by the operation of such factors as 
fatigue, loss of interest, practice, fluctuations of attention, etc., 
S will give 9 or 10 correct judgments in the former, and fewer than 
8 in the latter test. 

Variations of Method. — Test the discriminative capacity of 
each eye separately, as well as in conjunction. Employ the trial 
frame of Test 14, placing the solid disk before the untested eye. 
Care must be taken to avoid visual fatigue under these conditions. 
This variation of method is of interest in connection with recent 
work on psychophysical asymmetry and the relations between 
right-handedness, right-eyedness, right-earedness, etc. (See, for 
example. Van Biervliet). 

If means are at hand to secure effective constant illumination 
by artificial light, this may be tried for comparison with daylight 
illumination. 

^ It is convenient to prepare on small slips, beforehand, a number of 
chance orders, and to follow one of these with each set of 10 trials. 



TEST 17: DISCRIMINATION OF BRIGHTNESS 163 

Treatment of Results. — For comparative purposes, S may be 
ranked in terms of the arbitrary units afforded by the card-num- 
bers. For more exact quantitative expression, however, the re- 
sults should be expressed in terms of the brightness-differences 
which correspond to the card-numbers. This correspondence 
must be worked out by E for the papers employed. Full direc- 
tions for a simple and sufficiently accurate photometric determina- 
tion of brightness values of gray papers will be found in Titchener 
(Ft. I., 35 ff.). 

B. DISCRIMINATION OF BRIGHTNESSES TRANSMITTED LIGHT 

Apparatus. — Headrest. Brightness discrimination test (Fig. 
41). [This is a box fitted with a high power frosted tungsten lamp, 
the light of which is reflected from two independently adjustable 




FIG. 41. APPARATUS FOR BRIGHTNESS DISCRIMINATIONS. 

white screens upon two oblong, translucent windows, so placed in 
the face of the box as to give the same dimensions and spatial 
relations as obtained in the case of the gray strips.] 

Preliminaries. — The lamp cord is to be attached to a suitable 
current (106-110 volts, unless special lamps are ordered). E 
should endeavor to conduct the test in a dark or darkened room. 
If a brightly lighted room must be used, the effectiveness of the 
illumination of the ' windows' may be increased by erecting a pro- 
tecting screen of cardboard or cloth around them. 

Method. — It is important to arrange the headrest so that S is 



164 SENSORY CAPACITY 

directly in front of the apparatus, with his eyes on a level with the 
windows in the box. The distance is less important; 50 cm. will 
be found convenient. The degree of illumination is controlled 
by two levers, which move the reflecting screens, and which are 
{>r()vided with scales upon the upper siu-face of the box. E first 
sets the right-hand lever at the point which affords the maximal 
illumination of the right-hand window, and records the scale- 
reading exactly. In accordance with the methods just outlined 
for the discrimination of grays, E now determines the just dis- 
criminable difference in the setting of the two levers (when either one 
of them is at the maximal point). The same precautions must, of 
course, be taken to reverse the standards in order to correct the 
space error.^ 

Variations of Method. — Substitute a 32 C. P. ruby lamp for 
the frosted lamp, and determine the discriminative capacity for 
reds of different brightness. Other colors may be employed sim- 
ilarly in this apparatus. 

Results. — (1) Trained observers, working under conditions 
similar to those prescribed, can discriminate a brightness differ- 
ence of r2o, though this fraction is appreciably altered by changes 
of technique or of experimental conditions. Untrained observers 
have less efficiency, about sV, according to Spearman. 

(2) By a different method and with colored stimuli, Gilbert 
found that discriminative ability increases very gradually up to the 
age of 17, but exhibits marked irregularities at the age of 7. 

(3) In discrimination of shades of color, one may conclude from 
studies by Nichols (5), Gilbert (3), and Thompson (7), that women 
and girls very slightly exceed men and boys in this capacity. Luckej'-, 
however, concluded that no sex differences could l)e demonstrated 
in color discrimination. 

(4) Individual »S's are apt to possess a constant space error, i.e. 
to tend to judge the gray on one side darker; in some cases this is 
the right, and in others the left, but it seems impossible to correlate 
this asjaiiinetry with right and left-iiandedness (Spearman). 

(5) Gilbert found no very decidinl correlation between visual 

' Since the scales are identical and the entire instrument is symmetrical, 
a given setting of the lever will produce the same intensity of illumination 
for either window. 



TEST 17: DISCRIMINATION OP BRIGHTNESS 165 

discrimination and intelligence. Spearman's experiments upon 24 
village-school children give correlations between brightness discrim- 
ination and common sense, school cleverness, and general intel- 
ligence in the neighborhood of + 0. 50. In a series with high-class 
preparatorj^-school boys, however, school place and brightness 
discrimination gave only -\- 0.13 for the 'raw' correlation. 

Notes. — It is imperative that the conditions under which the 
gray strips are observed should be kept as constant as "possible. 
Backgrounds, cards, and holder provide these conditions in part, 
and relative brightness is not affected within a fairly wide range of 
illumination: nevertheless, it is desirable to work in the same place, 
at the same time of day, and under closely similar conditions of out- 
door illumination, e.g., between 9 a.m. and 3 p.m. on sunshiny 
days, and at a north window. To ensure evenness of illumination 
and absence of any shadows, E should test the setting of the ex- 
periment l^y placing Card No. in the holder and reversing its 
position several times. As this card represents objective equality, 
any constant judgment of difference may serve to indicate un- 
even conditions of illumination. 

In working with brightness differences, and indeed, with all 
small differences, E must be very careful to avoid suggestion of 
the direction of the difference to .S, and must keep a persistent 
watch for all kinds of secondary criteria of judgment. If desired, 
one could experimentally determine the degree of objective bright- 
ness difference that could be overcome. by suggestion. 

REFERENCES 

(1) W. Ament, Ueber das Verhaltniss der ebenmerklicheu zu den iiber- 
merklichen Unterschieden, etc., in Ph. S., 16: 1900, 135-196. 

(2) J. Frobes, Ein Beitrag iiber die scgenannten Vergleichungen iibei'merk- 
licher Empfindungsunterschieden, in Z. P., .36: 1904, 344. 

(3) J. A. Gilbert, (o) Researches on the mental and physical development 
of school children, in Yale S., 2: 1894, 40-100. (6) Researches upon school 
children and college students, in Iowa S., 1: 1897, 1-39. 

(4) G. Luckey, Comparative observations on the indirect color range of 
children, adults, and adults trained in color, in A. J. P., 6: 1895, 489-504. 

(5) L. Nichols, On the sensitiveness of the eye to colors of a low degree 
of saturation, in Amer. J. Science, 30: 1885, 37. 

(6) C. Spearman, General intelligence objectively determined and meas- 
ured, in A. J. P., 15: 1904, 201-293. 



166 SENSORY CAPACITY 

(7) Helen B. Thompson, The mental traits of sex, Chicago, 1903. Pp. 
188. 

(8) E. B. Titchener, Experimental psychology, vol ii., N. Y., 1905. 

(9) E. Toulouse, N. Vaschide, and H. Pi^ron, Technique de psych, experi- 
mentale, Paris, 1904, Pp. 330. 

(10) J. van Biervliet, L'asym^trie sensorielle, in Bull. Acad. Royale des 
Sciences, etc., de Belgique, 34: S6rie iii., 1897, 326-366. 



TEST 18 

Auditory acuity.— This test, like that of visual acuity, is pri- 
marily conducted for hygienic and practical purposes, especially 
in the examination of the physical condition of school children, 
and constitutes the chief auditory test. We may distinguish be- 
tween simple acuity tests, which are designed merely to detect the 
existence of lessened aural efficiency and roughly to measure its 
degree, and more elaborate tests of a diagnostic character, which 
are for the most part, not used in group investigations, but are con- 
fined to the work of specialists in otology or in the psychology of 
audition.^ Among the latter tests may be mentioned that of bin- 
aural pitch-difference, integrity of the tonal scale, bone vs. air-con- 
duction, determination of relative and absolute deafness, diagnostic 
speech-tests, etc. These tests are designed to investigate the 
functional efficiency of the various auditory structures, such as the 
tympanum, ossicles, cochlea, auditory nerve, and to determine 
the cause of the defect in hearing and the possibility of alleviating 
it by medical treatment. In particular, it is important, from this 
point of view, to differentiate between defect in the middle, and 
defect in the internal ear, because in the former case partial deaf- 
ness may often be relieved, whereas in the latter medical treatment 
is ordinarily of no avail. 

The more common and widely employed tests for acuity fall 
naturally into two main groups, viz : speech tests and instrumen- 
tal tests. Speech tests may be conducted by either vocahzed or 
whispered speech, and by either the method of extreme range or 
the method of percentage of accuracy. For instrumental tests, 
use is most often made of the watch, of some form of audiometer, or 

' A typical illustration is given by the interesting article of Bingham (4. ) 



TEST 18: AUDITORY ACUITY 167 

acoumeter, or of a tuning fork. The relative merits of these tests 
deserve brief consideration. 

The primary advantage of speech tests is that they measure directly the 
most important function of the ear — the hearing of conversational speech, 
whereas all instrumental tests, because they test the perception of only a 
limited number of auditory qualities, fail to give unequivocal indication of 
auditory efficiency. One may hear the watch at a considerable distance 
and yet be relatively deaf for speech, or conversely. Speech tests should, 
accordingly, be given the preference where possible. 

The use of speech tests is, however, rendered difficult for several reasons. 
(1) Speech involves a great variety and complex combination of pitches of 
varied intensity and clang-color, and these elements are further varied by 
changes in accent, emphasis, and inflection. To render speech tests avail- 
able, therefore, most careful study must be made of the elements of spoken 
and whispered speech, and lists of test-words must be prepared in the light 
of this analysis.^ 

(2) Examiners can not guarantee uniformity of enunciation and intensity 
of stress in conducting the test, so that the results of different E's, or even 
of the same E at different times, are rendered difficult of comparison. This 
difficulty must be met both by preliminary practise and care on £'s part, 
and by ranking S's relatively, in terms of the empirically determined norms 
for each particular test. 

(3)The acoustic properties of the room in which the test is held markedly 
affect its outcome. The method of relative ranking, coupled with the method 
of constant range (described below), must be used to meet this difficulty. 

(4) Unavoidable noises are more likely to interfere with speech tests than 
with tests conducted at close range, e. g., by the audiometer. To offset this, 
tests must be conducted in as quiet a room as possible, and doubtful cases 
must be retested under the most favorable conditions that can be secured. 

Limits of space will usually preclude the use of vocalized or conversa- 
tional speech, but whispered speech may be used for tests in a range of from 
17 to 40 m., or about one-third that of vocalized speech. Whispering re- 
duces the intensity of the vowels, whereas consonants are little changed. 
This test serves perfectly well for the practical examination of hearing and 
should be employed whenever feasible. 

In the use of both speech and instrumental tests it has been customary to 
employ the method of extreme range. A range line is chalked off on the floor 
of the room; S is seated at one end of this range, while E moves methodically 
forward and backward over it, until he determines the extreme limit of 



' This work has been done by Wolf (20). English number-word lists have 
been prepared and tested by Andrews (1). Reference to these writers will 
make clear why disparate words form the best speech-test material, and why 
numl)ers form the best type of words. Politzer's objection to numbers (11, 
p. 117) is answered by Bezold (2, p. 5; 3, p. 206). 



168 



SENSORY CAPACITY 



auditory capacity for the voice or instrument. The careful experiments 
of Andrews (1) have revealed most serious errors in this method, due to 
variation in the reflection of sound waves when E changes his position in 
the room. In other words, intensity does not decrease in any uniform man- 
ner as distance increases, and consequently there is no constant relation be- 
tween length of range and goodness of hearing. It is probable that this error 
has entered into practically all tests conducted indoors by this method. 
The only way to avoid it is to use the method of constant range, i. e., to keep 
the distance of the range, and thus the acoustic conditions, constant, and 
to measure acuity in terms of the percentage of errors made in a series of 
tests at this selected range. Furthermore, since there are distinct differ- 
ences in the audibility of different syllables, it is imperative to employ only 
selected lists of test-words, and to employ a sufficient niunber of them to 
include all the desired vocal elements. 



V^ 



1/ 



FIG. 42. politzer's acoumeter. 
From Titchener, Experimental Psychology. 
Reverting to instrumental tests, we find that the watch is most widely 
used. Its advantages are its convenience and accessibility and its relatively 
short range. Its disadvantages are that, like any instrument, it fails ade- 
quately to test the capacity to perceive speech, that its sounds give rise 
to a perception of rhythm, that its ticking is so familiar that illusions of 
hearing are frequent, and that watches vary in the intensity and quality 
of their ticks. ^ 
^ Various forms of acoumeter have been invented to meet the deficiencies 
of the watch. The instrument invented by Politzer (Fig. 42) is best known 



' Statements sometimes made in books on hygiene that, if the ticking of 
a watch can be heard at so-and-so many inches, the subject has normal 
hearing, are obviously absurd. The normal range for a watch-tick is 
given at 2.5 to 4.5 m., but one in the author's possession has a range of 12 m. 
See Bezold (3) and Sanford (11, p. 55). 



TEST 18: AUDITORY ACUITY 



169 



and is extensively employed in clinical work. Its range is commonly given at 
15 m., but will vary one or two meters from this, as test conditions vary. 
This acoumeter yields a brief tone, 512 vibs., of constant intensity. Hear- 
ing is tested by the method of extreme range. 

For description, see Politzer (11, pp. 107-8). The upright is held between 
the thumb and forefinger, and the small hammer is dropped upon the steel 
cylinder from a constant height. A small disk attached to a pin, not shown 
in the cut, is usr-d for Ijono-conduction and othei' diagnostic tests. 




FIG. 43. seashore's audiometer. 



Lehmann's acoumeter (Fig. 44), which is here prescribed, has the advan- 
tage of allowing variation of intensity, and is thus adaptable to the space 
limits of the ordinary laboratory.^ 

The acoumeter described by Toulouse, Vaschide, and Pieron (15) sub- 
stitutes a drop of distilled water for the metallic ball, and an aluminum disk 
for the receiving plate. 



For descriction, see Hansen and Lehmann (7). 



170 



SENSORY CAPACITY 



Many attempts have been made to devise an instrument that will permit 
testing at the ear itself, in order the better to rule out disturbing noises. 
Commonly, these devices are electrical in nature, and are planned to utilize 
a telephone receiver in which clicks or tones are produced in a graded series 
of intensities. Typical of these instruments is Seashore's audiojneter (Fig. 
43), which lias been fully described by its inventor (14), and which has been 
extensively employed by him (15) and by others, e. g., by the Child Study 
Bureau at Chicago (9, 16). The results that have been obtained by all 
instruments of the telephone type have apparently been rendered unreliable 
by physical errors (particularly by variations in the sensitivity of the 
telephone receiver), which are difficult to eliminate.^ 

Timing fo7-ks may be employed for acuity tests in accordance with the 
method first suggested by Von Conta (19), in which a 512 vibs. fork is struck 
and brought before the ear to be tested, and acuity determined by the length 
of time it can be heard. Blake's fork (Fig. 45) is devised especially for use 
by such a method, and may also be used for simple diagnostic tests as de- 
scribed in detail below. 

A. WHISPERED SPEECH TEST 

Materials. — Meter stick. Telegraph snapper, for signalling. 
A number of small rubber stoppers, for ear plugs. List of 100 test- 
numbers arranged in ten series, as in the following Table. 



table 25 

Test-numbers for A uditory A cuity {Andrews ) 





II 


in 


IV 


^ 


VI 


VII 


VIII 


IX 


X 


6 


84 


19 


90 


25 


14 


8 


52 


73 


24 


29 


69 


53 


7 


13 


31 


93 


35 


41 


95 


42 


17 


34 


39 


46 


9 


27 


64 


16 


62 


87 


92 


28 


62 


7 


65 


60 


81 


95 


49 


53 


33 


97 


84 


54 


98 


15 


6 


57 


80 


94 


26 


45 


21 


70 


76 


74 


19 


38 


71 


70 


50 


72 


56 


91 


40 


36 


78 


20 


16 


35 


75 


60 


75 


83 


23 


49 


40 


89 


3 


18 


48 


3 


43 


68 


52 


82 


23 


64 


58 


61 


1 


86 


18 


92 


87 


51 


97 


2 


37 



Preliminaries. — Select, if possible, an oblong room of average 
proportions and a length of at least 30 m. By rough preliminarj^ 

' For an extended discussion of the tecnnique, and particularly of the 
calibration of this type of apparatus, consult Bruner (5). 



TEST 18: AUDITORY ACUITY 171 

tests, establish a range in this room such that not over 90 of 100 test- 
words can be correctl}^ heard by a normal ear. If space will not 
permit this range to be established otherwise, interpose screens 
between E and S, or place E and *S in adjoining rooms, off a straight 
hne. The range may thus be cut dowTi to from 18 to 20 m., or even 
less. Whatever may be the arrangement that affords a suitable 
range, make careful note of all acoustic conditions, e.g., distance of 
range from walls, dimensions of rooms, exact position of E and S, 
disposition of large pieces of furniture in the rooms, number of doors 
or windows opened or closed, time of day, etc. Be sure always to 
work under precisely these conditions. 

Method. — (1) Seat S at the end of the range selected, with his 
right ear toward E. Carefully close the left ear by means of a rub- 
ber stopper inserted into the meatus. 

This must completely close the ear, but must not be distressingly tight. 
E should practise on himself beforehand. If both ears are properly stopped, 
the ticking of a fairly loud clock can be heard only with difficulty when 1 
or 2 m. away, and an ordinary watch cannot be heard when held close to 
the ears. The plug of cotton often used is entirely inadequate. Inserting 
the moistened finger-tip into the meatus makes an effective plug, but the 
position is uncomfortable, and *S is likely to move the finger and thus to cause 
distracting noises in the stopped ear. The same objection may be made 
to the practise of stopping the ear by pressing in the tragus, or by closing 
the meatus with the fleshy part of the ball of the thumb. 

Direct S to close or shield his eyes during the test, and on no 
account to watch ^'s lips. His mouth must hkewise be closed, 
since hearing is altered when the mouth is opened. 

Give S a short preliminary series without recording results, until 
satisfied that he understands the conditions of the test and feels at 
ease. 

(2) For the more formal test, pronounce the 100 words (or but 
50, if time is limited) in groups of 10, in the following manner: at the 
conclusion of one expiration, snap the sounder once as a ready sig- 
nal for *S: at the conclusion of the next expiration, pronounce the 
test-number in whispered speech with the residual air in the lungs : 
then snap the sounder twice to indicate that the word has been pro- 
nounced, and let S either speak or write down the number that he 
has heard (using a dash if nothing is heard). Meantime, E inter- 



172 SENSORY CAPACITY 

polates three complete breaths, then gives the warning signal, then 
the test-number after the fourth breath, and so on until 10 test- 
numbers are given. After a brief rest, try the second 10 numbers, 
and similarly, the third, fourth, etc. To avoid possible error, let 
S, if he is writing his report, begin a new column with each ten. 

(3) Stop »S',s right ear and test his left ear in the same manner. 

(4) T(»st *S"s binaural hearing by letting him /ace E, but with 
precaution that he does not secure visual aid from E's lips. This 
test is important, because binaural hearing may not be related to 
monaural range, and it is the type of hearing actually used in daily 
life. If time is very restricted, test this form of hearing alone. 

Treatment of Results. — *S's acuity is determined by the per- 
centage of test-numbers correctly heard, in relation to the normal 
percentage which has been ascertained by averaging the percent- 
ages of all >S"s tested under the same conditions. Thus, if the nor- 
mal percentage be 70, and *S's be 60, his acuity is 6/7; if S's be 80, 
his acuity is 8/7, i.e., supra-normal. Credit may be allowed for 
partially correct reports, e.g., 62 for 65: such allowance is specially 
recommended if 50 or fewer test-numbers are used. 

Notes. — The sounder is used to avoid changing E's vocal 'set.' 

If during the test, S becomes restless or inattentive, defer its 
completion. 

It is best to test but one *S at a time: two S's may, however, be 
placed back to back, for testing the right ear of the one and the left of 
the other, if precaution is taken to ensure against commmiication or 
disturbance. If the room is large, and preliminary tests warrant 
the belief that acoustic conditions will be identical, more *S's may 
be tested by seating them on an arc equidistant from E. 

A very crude group test may be carried out by placing all the chil- 
dren in a room at the limit of the ordinary classroom distance. Let 
them all close their eyes; then order them in a whisper to perform 
some unusual movement, such as to place the right forefinger on 
the palm of the left hand. Repeat with similar commands. Note 
any children who fail to respond, or who do so in evident imitation 
of others. Give these more careful tests later. Or take smaller 
groups of 10, similarly placed across the classroom. Provide each 
with a block of paper and pencil. Try a series of 10 whispered num- 
ber-words, and let each write them as heard. Test carefully any 
who make a single error. 



TEST 18: AUDITORY ACUITY 173 

B. ACOUMETER TEST 

ApparatT'S. — Lehmann acoumeter, provided with glass, copper, 
and cardboard receiving plates (Fig. 44). Small level. Meter 
stick. 

Preliminaries. — Select a room with a straight range of at least 
10 m. Seat S at one end of this range (10 m.) with his unused ear 
plugged, eyes and mouth closed, as in the speech test. Place the 



FIG. 44. lehmann's acoumetek. 
(Improved by Titchener.) 

aeoumeter upon a table at the other end of the range, and adjust it 
to a true horizontal plane by means of the test-level and levelling 
screw. Use the steel ball and the glass receiving plate, if only one 
plate can be tested. 

Method. — (1) Conduct a series of preliminary trials to familiar- 
ize S with the test conditions. Give a verbal 'now' about 2 sec. 
before the ball is dropped. Let S report 'yes' or 'no' after each trial. 
Introduce a few check tests, i.e., tests in which the 'now' is spoken, 
but the ball is not dropped. From these trials, E can determine 
approximately the 'critical' height for S. 

E manipulates the acoumeter with his right hand, using thumb and fore- 
finger to press the forceps, and thumb and middle-finger to turn the milled 
head of the screw on which the forceps rest. The shot is picked up with the 
left hand and placed in the rounded cavity in the tip of the forceps. Be- 
neath the instrument will be found a vertical millimeter scale. A fiat disk 
attached to the vertical screw just grazes this scale, while the disc is divided 
by cross lines into quadrants, so that variations in height of \ mm. or less 
may easily be secured. By setting the disk at zero and working upward, 
the height of fall may be noted without further reading of the vertical scale, 



174 SENSORY CAPACITY 

simply in terms of quarter-turns of the screw. E must practise this manipu- 
lation until it becomes automatic; special care must be taken to make a 
clean release of the shot, without swerving from the point just over the center 
of the receiving plate. 

(2) Conduct a series of 10 trials from a constant height, so chosen 
as to lie probably just above ;S's hearing capacity. If this is done, 
he should then report correctly all ten trials. It is understood that 
several check tests are added to the series of 10. 

(3) Reduce the height of fall by a half turn, 0.5 mm., and give 
anofther similar series of 10 trials, with check tests added. If S 
answers correctly, reduce the height by another half turn, and con- 
tinue in this manner, until there is found a set of the screw at which 
S begins to make errors. It is well to confirm the result by taking 
series with a still smaller fall. 

Treatment op Results. — The last correctly given series may 
be taken as the measure of S's capacity. His acuity is measured, 
as in the previous test, by his relation to the norm or average result 
determined under the same conditions. In physical terms, S's 
capacity can be indicated by stating the conditions, distance from 
the instrument, material used for receiving plate, and indicating 
the physical measure of the noise produced, i.e., in mg.-mm. The 
ball should be weighed upon sensitive scales to secure this index. 

Typical Results. — Lehmann's results for average »S's at 10 m. 
are: with glass plate 540 mg.-mm.; with copper plate, 1110 mg.- 
mm.; with cardboard plate, 225 mg.-mm.^ Other experimenters 
report lower limens, e.g., 500 mg.-mm. with the copper plate. 

Results obtained by analogous methods are those of Schafhautl, 
who found that the noise made by the fall of a cork pellet weighing 
1 mg. from a height of 1 mm., upon a glass plate, could be heard 91 
mm., and of Norr, who found that with small iron balls dropped 
upon an iron plate, the normal limen for 50 cm. distance was 1500 
mg.-mm. 

Notes. — All work with liminal stimuli is difficult, and this is 
especially true in audition. In the present test, S may imagine that 

1 These figures are for a 'plate' 1x1 cm. in size and 1 mm. thick. It a 
larger plate is used, as in the regular equipment, the limen is altered. 
Thus, with the glass plate, Lehmann and Hansen report 432 mg.-mm., 
with the area increased to 1 x 2 cm., and 16 mg.-mm. when the area was 
increased to 1 x 3 cm. 



TEST 18: AUDITORY ACUITY 



175 



he hears the ball drop when it does not. Check tests are demanded 
for this reason. Occasionally an S may be found so 'imaginative' 
that the test can not be successfully used. The only remedy is to 
try to increase his caution by informing him of his errors. 

C. TUNING FORK METHOD 

Apparatus. — Blake's fork (Fig. 45). Stop-watch. [Rubber 
tube.] 

Method. — (1) Stand directly behind *S. Sound the fork by 
pressing the tips of its prongs together until they touch, and then 
suddenly releasing them. Hold it opposite, and close to the ear to 
be tested, with its plane of vibration vertical. Lift the prongs 



FIG. 45. Blake's fork. 
For acuity and diagnostic tests by the temporal or ' ringing-off ' method. 

away from the ear occasionally, so that S can state more easily 
when it actually ceases to be heard. Record the time by means 
of the stop-watch. Repeat 5 times with each ear, or until ac- 
cordant times are given. Compare this time with the norm previ- 
ously established empirically for the fork in use. 

(2) For a simple diagnostic test, place the stem of the sounding 



176 SENSORY CAPACITY 

fork between *S's teeth. If both ears are normal, S will hear the 
tone with equal intensity in each ear, or the tone may be subjec- 
tively located in the middle of the head. If, however, one ear is 
defective, the tone may be heard either more loudly or less loudly 
in the affected ear. If the tone is heard more loudly in the ear 
which previous tests have shown to be defective, we may expect 
that the location of the defect on that side is in the middle or exter- 
nal ear, and that it may yield to proper medical treatment. If, on 
the contrary, the tone is heard better in the good ear, we may expect 
that the defect on the other side lies in the internal ear, or in more 
deeply seated portions of the auditory mechanism, and that it will 
probably not yield to treatment. 

General Results and Conclusions.— (1) It is difficult to 
state the prevalence of defective hearing in school children, because 
of the arbitrary and loose nature of the tests that have been used, 
and the varying standards that have been set for normality of hear- 
ing. Thus, in New York City, a recent report indicates only 1.1 
per cent defective hearing; but here the test consisted merely in 
the use of a few whispered words in the school room at 20 feet dis- 
tance. The extensive Chicago tests,^ conducted with Seashore's 
audiometer upon 6729 children, show that, if a pupil is classed as 
defective when the audiometer record is four points or more below 
the norm (indicating a defect such that "he would be seriously 
inconvenienced in detecting sounds of medium intensity"), 1080, 
or 16 per cent, of the number were defective in one or both ears 
(6.64 per cent in both, and 9.55 per cent in one ear). A defect 
equivalent to three or more points of the audiometer scale was found 
in one ear in 26.3 per cent, and in both ears in 12.3 per cent of those 
examined . 

Other examinations are summarized l)y Young (21) as follows: "Sexton, 
of New York, examined 575 school children, of which 13 per cent were hard 
of hearing; W. von Reichard, testing with the watch 1055 pupils of the gym- 
nasium of Riga, found 22.2 per cent with defective hearing. Weil, of Stutt- 
gart, tested the sense of hearing in .5905 scholars of various kinds of schools, 
and found it below the normal in from 10 to 30 per cent of the children, ac- 
cording to their social condition. Moure, of Bordeaux, found 17 per cent; 



See Smedley (16), Macmillan (8, also summarized in 12). 



TEST 18: AUDITORY ACUITY 177 

Gelle, of Paris, 22 to 25 per cent; Bezold, of Munich, 25.8 per cent of pupils 
with hardness of hearing." See also Chrisman (6) for a summary of inves- 
tigations prior to 1893. 

(2) With regard to the partially deaf, Macmillan and Bruner (9) 
conclude that, in theory, there exist varying degrees of deafness, 
"ranging all the way from slight and temporary impairment of 
hearing due to a cold, to the stage of absolute and permanent 
silence." An examination of the children attending the public 
day-schools for the deaf in Chicago, however, showed a somewhat 
unequal division of these pupils into 5 classes, based upon the 
somewhat conventional and immediately practical test of the status 
of the pupil in hearing in his schoolwork. Thus, of 174 cases, 55 
were classed as totally deaf, 33 as ''practically deaf" (hearing only 
intense and continuous sounds), 53 as possessing "a degree of hear- 
ing power" (hearing loud sounds, but not understanding vocal 
speech),' 25 as ''deaf for ordinary school conditions" (hearing only 
words spoken loudly and close to the ear), and 8 as "hearing chil- 
dren temporarily needing special training in articulation." 

(3) Differences between the two ears. Seashore (15) found 
decided differences in the acuity of the two ears, differences that 
were unknown to the *S's that exhibited them. Preyer, Fechner, 
and Bezold have concluded that the left ear tends to be the more 
acute: Bruner (5), however, as well as Miss Nelson (10), state 
that in both sexes the right ear is the more acute. Van Biervliet 
(18) asserts that inequality of hearing of the two ears is a universal 
fact, that the disparity is such that the poorer ear has a capacity 
i less than the better ear, l)ut that the right ear is the better in 
right-handed, the left in left-handed >S's. 

For practical purposes in connection with schoolroom tests, the 
determination of this difference is significant only when the inferi- 
ority of one ear is marked; in such cases, pupils should be so seated 
in the classroom as to bring their 'good' ear toward the teacher. 

(4) Seashore's tests (15) indicate that acuity improves with age 
u]) to 12 years: this improvement is due partly to the development 
of the ear, but is slightly affected by the growth in ability to under- 
stand and to undertake the test. 

' This class offers hope of improvement in hearing by means of mechan- 
ical devices for the intensification of speech. 



178 SENSOEY CAPACITY 

(5) There are no noticeable sex differences, according to Sea- 
shore. Lombroso concludes that men's hearing is keener than 
women's. 

(6) Seashore says there is "no indication that the bright children 
hear better than the dull children: there may be cases of children 
who are dull or are accounted dull because they do not hear well, 
but such cases are not common enough to be revealed clearly by 
our method, although there may be some indication of them." 
Nearly every other investigator, however, has found evidence to 
show that defective hearing has a positively injurious effect upon 
school-standing. 

At Chicago (16), the examination of 5706 pupils with Seashore's audiometer 
showed that pupils below grade have, at every age, more cases of defect 
than those at and above grade, and that pupils in the school for backward 
and troublesome boys have a greater percentage of defect than boys of the 
same age in other schools. At Copenhagen, Schmiegelow found that, of 79 
pupils regarded by the teachers as poorly endowed mentally, 65 per cent 
had defective hearing. Similarly, Gelle found 75 per cent of defect in the 
pupils classed as poorest. Permewan, at Liverpool, averaged the distance 
the watch could be heard by 203 pupils when divided into three groups^ 
bright, average, and diiU — and obtained the figures 51 inches, 47.3 inches, 
and 31.25 inches for these three groups, respectively. Shermunski, at St. 
Petersburg, by means of the whisper test, found that, among those of normal 
hearing, the ratio of good to poor students was 4.19 to 1; among those whose 
hearing was but 5 to 5 the normal, the ratio was 2.6 to 1 ; among those whose 
acuity was less than |, the ratio was 1.7 to 1. 

(7) Racial differences. Bruner's St. Louis Exposition tests (5) 
indicated that the whites were clearly superior in acuity to the other 
races tested. The Filipinos had the poorest hearing of those tested. 

(8) The simplest disturbance of hearing, if allowed to continue, 
may lead to serious results. In general, those who test the hearing 
of school children should note the condition of the ear, as well as test 
its capacity. Discharge of matter from the ear should be a cause 
for reference to medical attention. 

(9) Children who are partially deaf should be guided, in their 
adoption of occupation, to avoid callings for which they are unfitted, 
e.g., medicine, law, music, school-teaching, stenography, telephone 
or telegraph work, railroad, marine or military service. 

(10) The ears of school children should be tested carefully at 
least once in two years. 



TEST 18: AUDITORY ACUITY 179 

(11) Defective hearing, like defective vision, may exist in seri- 
ous degree and yet pass unnoticed by child, teacher, parents, or 
friends. Of the 13 per cent found defective by Sexton, only 3 per 
cent were themselves aware of any defect, and only one of them was 
known to be deaf by his teachers. 

Notes.— In testing the hearing of those who are known to be 
partially deaf, e.g., such a group as is mentioned in (2) above, the 
ordinary speech or instrumental tests are not serviceable. Use 
may, however, be made of the telegraph snapper mentioned in the 
first method, or of Blake's fork in conjunction with a 'differential 
tube.' 

The noise of the snapper can be heard by the average ear at a 
distance of some 150 m. or more. In testing the partially deaf S, 
it should be held slightly behind his ear, out of direct view, and 
employed like the Politzer acoumeter, i.e., by asking S to give the 
number of 'clicks' (2 to 5) that he hears. In very young *S's, suffi- 
cient indication of hearing may be obtained by watching for reflex 
starts of the whole body, or of some part of it. 

The differential tube, as used by Macmillan and Bruner (9) con- 
sists of a tube of soft rubber 100 cm. long, and 4 mm. internal diam- 
eter, fitted with hard rubber tips for insertion, one into *S's, and one 
into E's ear. After S has been familiarized with the sound of the 
fork by hearing it with the base applied to his front teeth, his ears 
are tested one at a time by placing the stem of the sounding fork 
upon the tube. On account, presumably, of the longer duration of 
the sound, this device may be used to detect a grade of hearing even 
lower than that detected by the snapper. 

REFERENCES 

(1) B. R. Andrews, Auditory tests, in A. J. P., 15: 1904, 14-56, and 16' 
1905, 302-326. 

(2) F. Bezold, Schuluntersuchungen liber d. kindliche Gehororgan, Wies- 
baden, 1885. 

(3) F. Bezold, Funktionelle Priifung des menschlichen Gehororgans, 1897. 

(4) W. Bingham, The role of the tympanic mechanism in audition, in P. R., 
14: 1907, 229-243. 

(5) F. G. Bruner, The hearing of primitive peoples: an experimental 
study of the auditory acuity and the upper limit of hearing of whites, 
Indians, Filipinos, Ainu and African pigmies, N. Y., 1908. (Reprinted from 
the Archives of Psych., No. 11). See especially 55-108. 



180 SENSORY CAPACI'l^Y 

(6) O. Chrisman, The hearing of children, in Pel. S., 2: 1893, 397-441. 

(7) F. Hansen and A. Lehmann, Ueber unwillkiirliches Fliistern. P'ine 
kritische u. exp. Untersuchung der sogenannten Gedankeniibertragung, in 
Ph. S., 11: 1895, 471-530, especially 494 ff. 

(8) D. Macmillan, Some results of hearing-tests of Chicago school children, 
in Medicine, April, 1902. 

(9) D. Macmillan (and F. G. Bruner), A special report of the Dept. of 
Child-study and Pedagogic Investigation on children attending the public 
day-school for the deaf in Chicago, Chicago, 1908. Pp. 88. 

(10) Mabel L. Nelson, The difference between men and women in the 
recognition of color and the perception of sound, in P. R., 12: 1905, 271-286, 
especially 280 ff . 

f(ll) A. Politzer, Lehrbuch d. Ohrenheilkunde, Stuttgart, 1893^ 

(12) Rept. com. on statistics of defective sight and hearing of public school 
children, in U. S., 1902, ii., 2143-2155. 

(13) E. C. Sanford, A course'in experimental psychology, Boston, 1895 and 
1898. Pp. 449. 

(14) C. E. Seashore, An audiometer, in Iowa S., 2: 1899, 158-163. 

(15) C. E. Seashore, Hearing-ability and discriminative sensibility for 
pitch, in Iowa S., 2: 1899, 55-64. 

(16) F. W. Smedley, Rept. dept. child-study and pedagogic investigation, 
in 46th An. Rept. Brd. Educ. Chicago, 1899-1900. Also in U. S., 1902, i. 
1095-1115. 

(17) E. Toulouse, N. Vaschide, and H. Pieron, Technique de psych. exp6r- 
imentale, Paris, 1904. Pp. 330. 

(18) J. van Biervliet, L'asymetrie sensorielle, in Bull. Acad. Royale des 
Sciences, etc. de Belgique, 34: Scrie 3, 1897, 326-366. 

(19) Von Conta, Ein neuer Hormesser, in Archiv f . Ohrenheilkunde, 1 : 
1864, 107-111. 

(20) O. Wolf, Sprache und Ohr, Braunschweig, 1871. Also various articles 
in otological journals, as Arch. f. Augen u. Ohrenheilkunde, 3: Abth. 2, 35, 
and Abth. 1, 125; and Zeits. f. Ohrenheilkunde, vol. 20. 

(21) A. G. Young, School hygiene, in 7th An. Rept. State Brd. Health of 
Maine, Augusta, 1892. Pp. 399. 



TEST 19 

Discrimination of pitch.— Like other forms of sensory discrimina- 
tion, this has been employed to discover the relation between such 
sensitivity and general intelligence. It has sometimes been 
employed to estimate musical ability, and it has, of course, general 
psychological interest. With adults and with children over eight 
or nine years of age, the test is relatively easy to administer. 



TEST 19: DISCRIMINATION OF PITCH 181 

The available instruments are air-blown reeds or bottles, vibrat- 
ing strings, as in the sonometer, and tuning forks. 

Experience shows that a set of finely tuned reeds may be employed only 
when they have 'settled' to their permanent pitch, when they are blown by 
an absolutely constant source of air-supply, and when their tone-color is 
uniform. This renders the reed-box, such as the Appunn tonometer, out of 
the question, save for well supplied laboratories. Gilbert's tone-tester (1), 
which is constructed from an adjustable reed pitch-pipe, varies as much as 
five vibs. in pitch with variation in the force with which it is blown. Stern's 
blown-bottles or tone-variators (6) necessitate a constant air-supply, and 
even then do not yield pitches which correspond to the attached scales. The 
sonometer or monochord, employed by Wissler (12) and Spearman (5), is 
rather unwieldy, not always constant in pitch and tone-color, and compli- 
cated by certain mechanical difficulties, while its pitches must be computed 
at each test in order to guarantee correctness of the assigned vibration-rate 
values. The instrument is defended, however, by Spearman (5, 243f). 
Wissler's method of using the monochord, in accordance with which S was 
obliged to manipulate the instrument, is indefensible, and his results are 
worthless, as far as pitch discrimination is concerned. The use of tuning 
forks in which the pitch of the comparison fork is varied by weights or riders 
(for illustration, see Titchener, 9, i., 68) also necessitates the computation of 
the pitch differences by counting beats, and both this and the manipulation 
of the riders is not easy for inexperienced E's. For these reasons, a series 
of carefully tuned forks, selected for uniformity of tone color, one for each 
pitch desired, is here recommended, after the example of Seashore (3) 
in his examination of the pitch-discrimination of children. The present 
apparatus (Fig. 46) has been described fully by the author in conjunction 
with Titchener (10).' 

Apparatus. — Set of 11 forks — one standard fork of 426§ vibs., 
and 10 comparison forks, whose rates are 0.5, 1, 2, 3, 5, 8, 12, 17, 23, 
and 30 vibs. below the standard. A resonance box on which the 
forks may be mounted as they are used. (Fig. 46) . Soft-tipped 
hammer for striking the forks. 

Method. — (a) Preliminary trials. Seat >S with his back to the 
table at which E works, and about 1 m. distant. Instruct him as 
follows: ''When I say 'now,' close your eyes and listen carefully to 

' Since the apparatus here prescribed was completed. Seashore has pro- 
posed to substitute for the resonance box, specially tuned resonators (per- 
haps two or three in number) of the Helmholtz type. By strongly re-enfor- 
cing the fundamental tone, these resonators might be particularly valuable 
in eliminating chance differences in tone color which are likely to appear in 
the small forks in use here. Otherwise, these differences must be eliminated 
by careful selection of the forks. 



182 



SENSORY CAPACITY 



the two tones you will hear; then tell me whether the second tone is 
higher or lower than the first. Say 'higher' if the second tone 
seems pitched above the first, 'lower' if below." 

<S's judgment must always be in terms of the second tone. To reques 
him to answer merely "same" or "different," as some investigators, e. gr., 
Gilbert, have done, would produce different results, as, in general, it is less 
difficult to judge a difference than to judge the direction of this difference. 

In this preliminary series, S may be allowed to give the answer "same," if 
ho naturally does so when he is unable to say "higher" or "lower." 




FIG. 46. TUNING FORKS FOR PITCH DISCRIMINATION. 

S's who are extremely unfamiliar with tones occasionally do not under- 
stand what is meant by 'higher' and 'lower,' and, like markedly unmusical 
or tonally-deaf S's, are apt to search for differences in intensity or duration 
of the tones instead of for qualitative (pitch) differences. In such an event, 
E must select two forks that give the maximal difference, and give S a short 
course of training by striking the forks in succession, and explaining after 
each pair that the second was higher or lower, as the case may be. If this 
training is futile, iS's discrimination must be extremely poor, and he may be 
ranked 30+. 



TEST 19: DISCRIMINATION OF PITCH 183 

Insert firmly in the oak pedestal, with their axes at right angles 
to the main axis of the resonance box, two forks that afford a large 
stimulus difference, e.g., the standard and the lowest fork (marked 
30). Damp one fork, e.g., the nearer one, by placing the left fore- 
finger on the tip of one of its prongs : sound the second fork by 
striking one prong a clean tap of moderate strength at a point 
about 1 the distance from its tip. Let the fork ring 4 sec, then 
damp it by resting the middle finger upon it. After an interval of 
2 sec, lift the forefinger, sound the first fork (while the 2d is still 
damped) and damp it similarly at the end of 4 sec. Keep these 
time relations — 4 sec. 1st tone, 2 sec interval, 4 sec. 2d tone — con- 
stant, and strike the forks as uniformly as possible in all tests. S 
always judges in terms of the second tone. 

Continue the practise series, in accordance with the general plan 
for discrimination work described in the opening pages of this chap- 
ter, by inserting other comparison forks in place of the "30" fork, 
giving sometimes the standard, sometimes the comparison stimu- 
lus first. This preliminary series is to familiarize *S with the general 
nature of the test, and to afford E a rough notion of the limits of 
»S"s discriminative capacity. For most S's, at least 4 or 5 min. 
should be given to this practise. 

(6) Test proper. If S's 'critical region' is not yet evident, give 
a formal series of pairs of stimuli, beginning with a supraliminal 
difference and passing toward subjective equality, until a difference 
is reached which S mistakes, or recognizes with diflEiculty. Keep 
this pair of forks on the resonance box, and give a series of ten pairs 
of stimuli — five with the standard first, five with the comparison 
first, but in an irregular order. In this series S must not be allowed 
to judge "same," but should be made to guess in case of doubt. He 
should know that two different forks are being used, but should not 
know the direction of the differences which he is judging. If he 
gives 10 correct judgments, select for the next series a comparison 
fork nearer the standard in pitch; if he gives but 5 or 6 correct 
answers, and these with difficulty, select a comparison fork farther 
from the standard. Seek a pair of forks which will yield about 8 
right cases in 10. Confirm the difference limen thus secured by 
trying series with comparison forks just sharper and just flatter 
than the one in hand. /S's discriminative capacity for pitch is indi_ 



184 SENSORY CAPACITY 

cated by the difference in viljrations between the standard fork and 
the comparison fork that yiekled 80 per cent right answers. 

Results and Conclusions. — (1) The difference li7nen for 
highly practised *S's in careful laboratory tests is, for this region of 
the tonal continuum, about 0.3 vib.' 

(2) There are large individual differences in the difference 
limen for pitch : some, even young children, can discriminate 2 vibs. 
with certainty; some are virtually tone-deaf. These differences 
are to be referred, in the main, to structural differences in the sense- 
organ. Some idea of the distribution of capacity in this test is 
afforded by Seashore's results, Table 26." 

TABLE 26 

Pitch Discrimination of 167 Children, Aged 6-15 Years. (Seashore.) 

NO. LIMEN IN VIBS. NO. i LIMEN IN VIBS. 



20 


1 to 2 


21 


12 to 30 


63 


3 " 5 


14 


Over 30 


48 


6 " 10 







(3) Seashore found no obvious sex differences in the discrimina- 
tion of pitch. BothWissler (12) and Thompson (8) found women 
superior to men, but their results are less reliable than those of 
Seashore. 

(4) The relation of pitch discrimination to age is not entirely 
clear. If we accept Gilbert's results, they indicate a correlation 
between age and capacity to the extent that children are least 
efficient at 6, improve rapidly up to 9, then gradually to 19, with 
exceptions at the ages of 10 and 15 — a seeming loss of capacity, 
which Gilbert is inclined to refer to pubertal and other physiological 
disturbances.^ Wissler's seniors surpass themselves as freshmen. 

1 For a summary of the work of Delezenne, Seebeck, Preyer, Luft, Meyer, 
and others, consult Titchener (9, Ft. ii., 235 ff.) 

2 These results are subject to the qualification that the figures obtained 
from those of the children under 9 years of age are not very reliable. In 
some 30 cases not here included, Seashore was unable to determine a limen 
within the time at his disposal. Gilbert found only 3 of 130 children who 
could not discriminate a half-tone, i.e., about 30 vibs. in this region, but as 
already stated, his S's were asked to judge only difference. 

^ Cf . similar disturbances found by Bryan at 10 and 15 in motor tests. 



TEST 19: DISCRIMINATION OF PITCH 185 

Seashore, however, discards results obtained from children under 
10, and can find no certain indication of improvement in discrimina- 
tion after that age. 

(5) Seashore found a slight positive correlation between pitch 
discrimination and auditory acuity (Test 18). 

(6) (a) Practise does undoubtedly improve pitch discrimina- 
tion, but investigators are not in agreement as to the extent of such 
improvement. It seems evident that its limits are fixed by ana- 
tomical and physiological conditions in the ear itself, and that these 
limiting conditions vary in different individuals. In general, the 
improvement is not as great as that observed in some other func- 
tional capacities, e.g., the discrimination of dual cutaneous impres- 
sions (Test 23), and is reached after a relatively short period of 
training. 

Seashore believes that maximal capacity can be attained after very little 
practise. In 20 days training, he found that some S's exhibited no improve- 
ment, while the maximal improvement reported was the reduction of the 
limen of an unmusical *S from 30 to 5 vibs. 

Spearman (5, p. 231) believes that 15 minutes fore-exercise will reduce 
the pitch-limen by an amount depending very largely upon S's previous 
general familiarity with tonal experiences. Thus, he computes a reduction 
for specially practised /S's from a limen of 0.5 (before the 'exercise') to 0.3 
(after the special exercise), for musicians from 4 to 2 vibs., for non-musicians 
of general culture from 10 to 4 vibs., and for European villagers from 30 to 8 
vibs. These figures would indicate that even a practised musical *S' profits 
by a preliminary 'warming-up,' and they emphasize the importance of giv- 
ing such fore-exercise to all S's. 

(b) Aside from practise in the narrow sense, i.e., special exercise 
in pitch-discrimination under experimental conditions, we may con- 
sider the effect upon discrimination of practise in the wider sense, 
i.e., of general musical training. Seashore is, again, very emphatic 
in his declaration that individual differences in pitch discrimination 
are not due principally to musical training, and Spearman's conclu- 
sion is that, "though a correspondence really does exist, yet it is 
not to the smallest degree of the specific character contemplated by 
those who talk of 'musical sensitivity, ' " i.e., by those who refer to 
pitch discrimination as a test of "musical sensitivity." 

To the author, this seems a case of one-way correspondence : an individual 
who cannot discriminate a half-tone cannot be musical, but an individual 



186 SENSORY CAPACITY 

who is not musical may have a perfectly good discrimination after a little 
preliminary practise. Given, however, a good natural capacity for discrim- 
ination, it is unquestionably true that musical training tends to keep this 
capacity up to the individual's physiological limit. In testing 50 grammar- 
school boys for pitch discrimination, the three best discriminators were 
found to be " taking lessons" on the violin. The author has also shown else- 
where (11) that in the case of an unpractised, unmusical »S, it may be possible 
to reduce the limen very decidedly by working under very constant, favor- 
able conditions — such as duration, intensity, timber of tones, time-inter- 
vals, etc., but that the slightest modification of these conditions will make 
discrimination very difficult or impossible. 

That one can argue from capacity in pitch discrimination to capacity to 
profit by musical instruction is asserted specifically by Seashore in another 
article (4, 76-7), where he says that, if the limen for pitch is .04 tone 
(about 2 vibs. in the section of the tonal continuum under test), the child 
may become a musician; if .06 to .16 tone, the child should have a simple 
musical education, including obligatory singing in the school; if .18 to .34 
tone, the child should have this musical education only provided special 
inclination for some kind of music is displayed, while participation in school 
singing should be optional; if the limen is .36 tone (18 vibs.) or over, the 
child should have nothing to do with music. 

(7) Seashore reported no correlation between jpitch discrimina- 
tion and intelligence, when general intelligence was indicated by 
class standing and teachers' estimates, and the correlation was 
worked out by the method of group-classification. Spearman 
terms this an " ingenious, " but somewhat ''disseminated "method, 
and by subjecting Seashore's results to his (Spearman's) methods, 
obtains from them a correlation index of 0.24 ± 0.07. From his 
own results, Spearman (5) concludes that general intelligence is 
correlated with pitch discrimination by the index 0.94, or, as he 
states, "The [Intellectual] Function is 9 parts out of 10 responsible 
for success in such a simple act as Discrimination of Pitch.'" 
Later, in conjunction with Krueger (2), Spearman computes a cor- 
relation of .83 between the capacity for pitch discrimination and the 
hypothetical '' central factor, "which is tentatively assumed to be a 
certain quality or degree of plasticity of the central nervous system. 

The author's tests of mental and physical ability in fifty 8th-grade 
boys included a determination of pitch discrimination, both with 
the Stern tone-variator and M'ith a monochord. These two tests 

' It is but fair to call attention to the fact that Spearman's formulas have 
been called in question. 



TEST 19: DISCRIMINATION OF PITCH 187 

showed a correlation of .83. The variator test, which was, on the 
whole, most reliable, showed a correlation of .27 with class standing. 

(8) Other correlations. Krueger and Spearman report 'raw'cor- 
relations between pitch discrimination and both adding and the 
Ebbinghaus completion test, of .67 and .59, respectively. After the 
apphcation of the expanding formula (No. 41, Ch. 3), these cor- 
relations become .80 and .81, respectively. Thus it appears certain 
to these authors (2, p. 78) that the capacity to discriminate pitch 
actually exhibits a very high degree of correlation with the seem- 
ingly fundamentally different capacities requisite in adding and in 
the Ebbinghaus test. 

The author found a correlation of .27 between pitch discrimina- 
tion and the discrimination of lifted weights. 

Notes. — With reference to musical ability, Stumpf (7, ii., p. 
157) proposes as tests of musical capacity: (1) discrimination, (2) 
ability to sing a note struck on the piano, (3) ability to judge 
whether one or two tones are present in various fusions, (4) skill in 
determining the relative pleasantness or unpleasantness of two 
chords separated by a short pause. M. Meyer denies the validity 
of the discrimination test for musical ability, and favors a form of 
test in which S is asked to state whether a given bass note does, or 
does not, form the proper fundamental for a given chord (played in 
the treble region of the piano). 

It is well to inquire of all *S's, before the test is administered, 
whether they are musical or not, whether they play any musical 
instrument, or sing, or are 'fond' of music. The author has found 
several instances of children who were quite unable to distinguish 
pitches several tones apart, but who were compelled by their teachers 
to take systematic instruction in singing along with other children in 
the pubhc-school classes. 

S's that fail to discriminate the 30 vibs. difference may be fur- 
ther tested by a piano to see whether they are absolutely tone-deaf. 
If time permits, it is of interest to see whether aS's with very poor 
discrimination can be improved by systematic practise. 

For best results, the discrimination test should be given individ- 
ually; if necessary to undertake group tests, it is better to work 
with small groups of 5 or 6 S's : supply them with pencil and paper ; 
let them number the trials and write their judgments — "H" for 
higher or "L" for lower — after each number. 



188 SENSORY CAPACITY 

REFERENCES 

(1) J. A. Gilbert, Experiments on the musical sensitiveness of school chil- 
dren, in Yale S., 1: 1893, 80-87. 

(2) F. Krueger and C. Spearman, Die Korrelation zwischen verschieden- 
en geistigen Leistungsfahigkeiten, in Z. P., 44: 1907, 50-114. 

(3) C. E. Seashore, Hearing-ability and discriminative sensibilit}^ for 
pitch, in Iowa S., 2: 1899, 55-64. 

(4) C. E. Seashore, Suggestions for tests on school children, in Educ. Rev., 
22: 1901, 59-82. 

(5) C. Spearman, General intelligence objectively determined and meas- 
ured, in A. J. P., 15: 1904, 201-293. 

(6) L. Stern, Der Tonvariator, in Z. P., 30: 1902, 422-432. 

(7) C. Stumpf, Tonpsychologie, 2 vols., Leipzig, 1883, 1890. 

(8) Helen Thompson, The mental traits of sex, Chicago, 1903. Pp. 188. 

(9) E. B. Titchener, Experimental psychology, vol. ii., Quantative experi- 
ments, N. Y., 1905. 

(10) E. B. Titchener and G. M. Whipple, Tuning forks for pitch discrimi- 
nation, in A. J. P., 20: 1909, 279-281. 

(11) G. M. Whipple, Studies in pitch discrimination, in A. J. P., 14: 1903, 
553-573. 

(12) C. Wissler, The correlation of mental and physical tests, in P. R. M. 
S., 3: No. 6, 1901. Pp. 62. 

TEST 20 

Discrimination of lifted weights. — We may compare two 
weights either by attending passively to the pressures set up when 
they are laid upon the skin, or by actively lifting or 'hefting' them. 
In the first instance, we see illustrated the procedure employed in 
testing discrimination of pressure (Test 21); in the second, that 
employed in testing discrimination of weight (in the narrow sense) . 
The latter form of discrimination is always the keener, since to 
cutaneous pressure, there are added sensations contributed from 
muscle, joint, and tendon, particularly from the tendon. Because 
it is the movement of lifting the weight that aids us in estimating 
its comparative amount, the determination of this form of dis- 
criminative capacity is sometimes loosely termed the measurement 
of the 'muscle sense,' or the 'muscle sense test.' 

Of the historical development of this important experiment, this 



TEST 20: DISCRIMINATION OF LIFTER WEIGHTS 189 

is not the place to speak.^ Attention is given here merely to the 
use of the experiment as a comparative test of mental or psycho- 
physical efficiency. The most important investigations of this 
type are those of Gilbert (3), Thompson (7), and Spearman (6). 
The test was also included in those administered iDy the author 
to 50 8th-grade boys. 

Gilbert used weights of the 'cartridge' pattern, similar to those here pre- 
scribed. His method was less exact than could have been desired : his school 
children had simply to sort out all the weights that were the same as the 
standard, 82 g. As there were but 9 comparison weights, yielding a maximal 
range of 100 g., Gilbert encountered numerous cases (see Table 27) in which 
no discrimination could be made within this range. 

Miss Thompson employed cartridge weights giving a range from 80 to 
100 g., and apparently found no difficulty infesting adults with this equip- 
ment. 

Spearman, similarly, employed cartridge weights with a standard of 1000 
grains and with a series of geometrical increments, as proposed by Galton 
(2, Appendix). It is to be noted that the smallest increment of the original 
Galton series, 1/100, proved too coarse to test the capacity of some of Spear- 
man's S's, while the largest increment (mentioned by Galton for use with 
"morbid" cases) proved too fine to test the capacity of others. 

A test carried on at Columbia University under the name "perception of 
weight" or "force of movement" consisted in lifting the handle of a spring 
dynamometer until it touched a stop. The 'reagent' then made 10 succes- 
sive attempts to pull the handle to the same point when the stop was re- 
moved. It is evident that the results cited by Wissler (11) for this test are 
not comparable with those obtained by the standard form of the weight- 
discrimination test. 

Van Biervliet (9) used weights of 500, 1000, 1500. and 2000 g. on the 'fav- 
ored' side of the body in the case of 100 S's that were tested by him for asym- 
metry in weight. The weights were lifted by a string attached to the index 
finger, and a simple gradation method was employed to determine the equiv- 
alent, for the left side, of a given weight on the right side of the body. The 
method is too unlike the standard method to admit of comparison of re- 

^ The stock laboratory experiment is described and its technical aspecst 
are discussed with sufficiently full citations of its literature by Titchener 
(8, Pt. I. 115 ff.; Pt. 11, 265 ff.). As Titchener remarks: "This may be 
regarded as the classical experiment of quantitative psychology. On the 
psychphysical side, it has engaged a long line of investigators: Weber him- 
self (10), Fechner (1) and Hering, all employed it to test the validity of 
Weber's Law; and a glance at the current magazines will show that the work 
begun by them has continued down to the present day. On the psychologic- 
al side, it has been made by L. J. Martin and G. E. Mliller (4) the vehicle 
of a qualitative analysis of the sensory judgment, the most elaborate and 
penetrating that we have." 



190 SENSORY CAPACITY 

suits. It may be stated, however, that the fraction 1/9, which the same 
author claims to have established as a constant of asymmetry in all sense- 
departments, was also found in this test, e.g., a weight of 450 g. in the left 
was equal to a weight of 500 g. in the right hand, etc. 

Apparatus. — Set of discrimination weights, comprising a stand- 
ard, 80 g., and 23 comparison weights, yielding the series — 80.5, 
81, 81.5, 82, 82.5, 83, 83.5, 84, 84.5, 85, 86, 87, 88, 89, 90, 92, 94, 96, 
98, 100, 105, 110, and 120 g. The weights are of identical size, 
shape, and color; are made of wood to avoid disturbing tempera- 
ture sensations, and are marked inconspicuously (with reversed 
numbers), so that their weight may be Imown to E, but not to S. 

Method. — Follow the general plan of procedure outlined in the 
introductory pages of this chapter. This plan embodies (1) a 
preliminary series of trials between the standard and various com- 
parison weights to familiarize S with the conditions of the test and 
to indicate to E the probable ' critical region' in which *S's limit of 
capacity will be found, (2) a more formal determination of this 
region by systematic procedure from too great to too small a stim- 
ulus-difference, (3) the selection from this region of a stimulus- 
difference (the standard and some single comparison weight) which 
may be expected to yield about 8 right judgments in 10, and which 
is given 10 times (5 times with the standard first, 5 with the com- 
parison weight first —the arrangement being determined by chance), 
and (4) the final determination of the difference that yields 8 
correct judgments in 10 by the trial of slightly smaller or slightly 
larger stimulus-differences, as may be required. 

In the application of this procedure to weight discrimination, the 
following suggestions may be made. S should take his position, 
standing, before the table upon which E has arranged the weights. 
*S's view of the weights must be cut off, either by a well-arranged 
blind-fold or by a horizontal cardboard screen so adjusted that he 
may lift the weights easily, but may not see them. In each trial, 
E selects a comparison weight, determines upon the order (stand- 
ard first or comparison first); then, with a warning 'now,' places 
the first Aveight between ;S's thumb and his first and second fingers: 
S hefts this weight, replaces it upon the table, when E quickly re- 
moves it and substitutes the second weight of the pair under trial, 
which is, in turn, hefted and replaced by S. The judgment must 



TEST 20: DISCRIMINATION OF LIFTER WEIGHTS 191 

then be given promptly by S and always in terms of the second 
weight: — "heavier," "lighter," or " equal. "^ The details of the 
manner of lifting the weights may, in general, be left to each S. 
Fechner allowed 1 sec. for raising, 1 sec. for lowering, and 1 sec. for 
changing the weight, so that each comparison required 5 sec. for 
its execution. 

Treatment of Data. — The difference between the comparison 
weight that yields 8 right judgments in 10 and the standard weight, 
80 g., affords the absolute difference limen. The fraction formed 
by taking this difference as the numerator and the standard weight 
as the denominator affords the relative difference limen, and is the 
common index of efficiency in the test, since relative capacity is 
found to be constant for a given individual within a wide range of 
absolute weights. It is, of course, the constancy of this fraction 
that constitutes the essential fact of Weber's Law. 

Results. — (1) Normal capacity. In one place, Weber cites as 
the average sensible discrimination for lifted weights for four ^'s, 
3/32; in another place, he gives 1/40 as the difference just distin- 
guishable by "quite the majority of human beings without any long 
preliminary practise" (10). Other authorities have placed the 
norm of performance at 1/17 or at 1/24 (Seashore, 5, p. 96). The 
author's tests with the apparatus and methods here described in- 
dicate for 8th-grade boys an average limen of 4.7 g. (standard 80 
g.). The corresponding fraction, 1/17 , is presumably close to the 
average performance for boys of this age. This result is corrob- 
orated by Spearman's series, which most nearly resemble the 
author's in method and apparatus; Spearman quotes 1/15 for a 
test made under unfavorable conditions and 1/20 for a test made 
upon older children under favorable conditions. 

(2) Individual differences. The work of every investigator has 
shown that the capacity to discriminate lifted weights differs very 
considerably among normal S's, even when age, sex, and practise 
factors are eliminated. The author found 7 boys in 50 who could 
discriminate 80 and 81 grams, and one boy who could just discrim- 

1 In tlie final test of 10 trials with a constant stimulus-difference, it is pref- 
erable to ask S to guess in case of an equal judgment; otherwise equal judg- 
ments may be recorded as wrong. S should not be permitted to return to 
the first weight after the second has been lifted. 



192 



SENSORY CAPACITY 



inate 80 and 97 grams : reference has already been made to the fact 
that several experimenters have found their weights inadequate 
to measure the wide differences in capacity that they encountered. 
(3) Dependence on age. Spearman's tests convinced him "that 
the younger children were almost equal to the older ones and both 
were not far from adults," and also that there is no appreciable loss 
in weight discrimination with the coming of old age. Gilbert, 
however, as Table 27 shows, found a gradual improvement in dis- 
crimination from the 6th to the 13th year. Developmental dis- 
turbances appear from 12 to 14, and discrimination apparently 
does not improve thereafter. 

TABLE 27 
Dependence of the Discrimination of Lifted Weights on Age (Gilbert) 



11 12 13 14 15 16 17 



Median Limen, 

Boys 

Median Limen 

Girls 

Per cent over 

18 g., Boys... 
Per cent over 

18 g., Girls... 



13. o! 13.2 
16.8 13.2 

26 j 36 

i 
49 j 40 



12.2 
11.0 
35 



10.2 
10.0 
23 
17 



10.2 
7.6 



12 5 



12 



6.0 
5 
5 




6.0 

6. 

2 

2 



6.0 
6.4 


2 



(4) Dependence on sex. Inspection of Gilbert's table shows in 
many, though not in all groups, evidence of superior ability on the 
part of boys. Miss Thompson, similarly, found men much super- 
ior to women, and is inclined to see in this relation the effect of the 
same factors that had made men superior in her several tests of 
motor ability. Spearman, however, contends that "the fluctuat- 
ing differences of sensory discrimination observable in connection 
with sex at the various stages of growth are chiefly and perhaps 
altogether a mere consequence of similarly fluctuating differences 
in intelligence" (6, p. 261). 

(5) Dependence on practise. The consensus of opinion is that, 
at least in comparison with many other mental activities, the dis- 
crimination of lifted weights is but little affected by practise. 
Thus, for instance, Biedermann and Loewit (quoted by Spearman) 



TEST 20: DISCRIMINATION OF LIFTER WEIGHTS 193 

found that a difference limen of 1/21 fell only to 1/23 at the con- 
clusion of a protracted research. It is also true that Fechner, 
who devoted most heroic amounts of time to weight discrimina- 
tion, did not thereby attain remarkable capacity. On the other 
hand, Spearman believes that nearly every S exhibits practise- 
improvement in the first stages of a test (say during the first 15 
min.), and that in some cases "the improvement is enormous." 

(6) Correlation with intelligence. Spearman's ' corrected' index 
of correlation between weight discrimination and general intelli- 
gence is 0.44. Gilbert apparently determined no correlation be- 
tween these two factors. The author's tests show no correlation 
with class standing. 

(7) Other correlations. The peculiar test of "perception of 
weight" used at Columbia University is shown by Wissler (11) 
to exhibit no correlation with accuracy of movement in striking 
dots or with accuracy in the 'size test' (drawing a line equal to a 
5 cm. directly observed standard). 

(8) A ' constant error' is exhibited by most »S's, in that they tend 
to overestimate the second weight. This, of course, makes it 
doubly imperative that the procedure be so arranged as to reverse 
the time-order in half the trials.^ 

REFERENCES 

(1) G. T. Fechner, Elemente der Psychophysik, esply vol. I. (Reprint, 
Leipzig, 1889, 1907.) 

(2) F. Galton, Inquiries into human faculty. New York, and London, 
1883. (Reprinted in Everyman's Library, No. 263.) 

(3) J. A. Gilbert, Researches on the mental and physical development of 
school children, in Yale S., 2: 1894, 40-100. 

(4) Lillie J. Martin and G. E. Miiller, Zur Analyse der Unterschiedsemp- 
findlichkeit, Leipzig, 1899. 

(5) C. E. Seashore, Elementary experiments in psychology, N. Y., 1908. 
Pp. 218. See especially Ch. viii. 

(6) C. Spearman, General intelligence objectively determined and meas- 
ured, in A. J. P., 15: 1904, 201-293. 

(7) Helen B. Thompson, The mental traits of sex, Chicago, 1903. 



'On othor qu'iIit;itivo aspects of this test, see especiallv Martin and 
Miiller (4.) 



194 SENSORY CAPACITY 

(8) E. B. Titchener, Experimental psychology. Vol. 11. Quantitative ex- 
perimeiTts, N. Y., 1905. 

(9) J. J. van Biervliet, L'Asymetrie sensorielle, in Bull. Acad. Royalc 
des Sciences, etc., de Belgique, 34: Serie iii., 1897, 326-366, esp. 330. 

(10) E. H. Weber, Der Tastsinn und das Gemeingeflihl, in Wagner's Hand- 
worterbuch d. Physiol., vol. 35, 1846. (Reprinted Separately 1869, 1851.) 

(11) C. Wissler, The correlation of mental and physical tests, in P. R. M. 
S.,3: No. 6, 1901. Pp.62. 

TEST 21 

Discrimination of pressure. — The determination of the dif- 
ference limen for pressure, like that for lifted weights (Test 20), has 
constituted one of the standard psychophysical experiments since 
the time of E. H. Weber, who utilized it in connection with other 
tests to establish the well-known law that bears his name. By 
experimenting with standard weights of 32 oz. and 32 dr., respec- 
tively, Weber was able to report that "a difference of the smaller 
weights is not less accurately distinguished by touch than the 
same difference of the larger weights." 

This test with 'resting weights,' sometimes termed the 'pressure 
sense' test, appears to have been less frequently used for functional 
and comparative purposes than the test with 'lifted weights.' 
Its feasibility depends very largely upon the type of apparatus em- 
ployed. Differences between the temperature of the weights and 
that of the skin, variation in the temperature of the weights them- 
selves, in the 'jar' of application, in the area and place of applica- 
tion, etc., must be excluded, since they inevitably produce conflict- 
ing results. To obviate these errors and to render the test more 
simple in execution and more reliable in outcome, the use of a 
'pressure-balance,' following the principle adopted by Merkel 
(7, p. 255) is desirable, if not essential. 

Other forms of pressure-balance have been elaborated by Jastrow (5) — 
figured by Sanford (8, pp. 417-8) and by Titchener (10, pt. ii.) — and by Bolton 
and Withey (1). The balance here prescribed has been designed by the 
author (11) to supply in a single relatively simple apparatus a device for 
determining both the capacity for pressure discrimination and sensitivitj^ 
to pain (Test 22). It may be regarded as a combination of the principle of 
Merkel's and of Jastrow's pressure-balances and that of Gilbert's balance- 
algometer (3). 



TEST 21 : DISCRIMINATION OF PRESSURE 



195 



Apparatus. — The author's pressure-pain balance (P^ig. 47). 
Cardboard screen with suitable supports. Seconds' pendulum 




Fig. 47. pressure-pain balance. 



(Fig. 21), or other noiseless device for controlling the time-relations 
of the test. 

Preliminaries. — Place the balance upon a low table. See that 
the beam of the instrument moves freely, but comes to rest in a 
horizontal position when no weights are applied : if necessary, turn 
the small screw in the tip of the arm inward or outward until this 
position of rest is secured. 

To assure comfort, the instrument should be so placed that aS's 
wrist will come just over the edge of the table; his elbow will not 
then be forced up into an awkward position, and his hand can lie 
upon the hand-rest, with the end of his forefinger projecting straight 
forward between the upper (stationary) and the lower (movable) 
tip of the balance. Adjust the upper tip so that it is in permanent 
contact with the center of the finger-nail, but does not touch the 
skin of the finger. 

Arrange the screen to cut off >S's view of the apparatus, or, if 
he be reliable, simply instruct him to close his eyes. 

Place the pendulum where its oscillations will be easily visible. 

Method. — The general plan of procedure is identical with that 
outlined in the introductory pages of this chapter, and recapitu- 
lated in Test 20. To apply this procedure to the test with the 
pressure-balance, after throwing the lever down to the right, place 



196 SENSORY CAPACITY 

the weight marked B-lOO g. on the pin marked B, at the outer end 
of the beam. This weight is not removed during the experiment, 
and constitutes the standard stimulus. Place upon the second pin, 
marked A, the desired increment weight — any one, or any com- 
bination, of the weights marked A. To apply a pressure-stimulus, 
move the release-lever up to the left, so as to depress the support 
beneath the beam of the balance. To remove the stimulus, move 
the same lever to the right. The increment-weights are added 
to the standard stimulus when they rest upon the beam at A : they 
are subtracted from the total pressure, at will, by depressing the 
increment-weight lever, which lifts them from the beam and allows 
only the standard stimulus, 100 g. to be operative. Thus, for 
example, to test the discrimination of 150 g. and 100 g., movethe 
release-lever down to the right, place upon the pin A the 30 g. and 
the 20 g. weights, and upon the pin B the 100 g. weight. Give S a 
warning "now," and 2 sec. later move the release-lever smoothly up 
to the left: allow the pressure (150 g.) to be felt for 2 sec, then 
move the release-lever to the right: immediately depress the 
increment-weight lever, and apply the second stimulus (100 g.) 
in the same manner, while this lever is held down. *S judges, 
always in terms of the second stimulus, saying " heavier," " lighter," 
or " equal. "^ 

The exact duration of the stimuli and of the interval between 
them is of less importance than constancy from trial to trial. 

To avoid local fatigue, at least 15 sec. should elapse between suc- 
cessive judgments. 

E must practise the manipulation of the instrument, and take 
particular precaution to move the release lever so as to avoid either 
too sudden application, which produces a disturbing 'bump' and 
vibration, or too sIoav application, which also renders the judgment 
more difficult.^ 

*S must be specially instructed to receive the stimulus passively, 
so far as his finger is concerned. A downward movement of 

1 Equal judgments, as previously explained, are to be avoided, if possible' 
in the final trials with a constant stimulus-difference. 

^ The author has found that some E's, bj^ a curious kind of unconscious 
'sympathy,' are inclined to apply the light pressure more gently than the 
heavier pressure. >S's judgments will almost certainly, even without his 
knowledge of it, betray the operation of this secondary criterion by exhibit- 
ing an unexpected and impossible delicacy of discrimination. 



TEST 21: DISCRIMINATION OF PRESSURE 197 

reaction in the finger tip converts the test, virtually, into a test of 
discrimination of lifted weights.^ 

Treatment of Data. — The calculation of the difference limen 
and of the discriminative sensitivity is similar to that in the pre- 
ceding test, save, of course, that the standard is now 100, instead 
of 80 g. 

Results. — (1) Normal capacity. The discriminative sensitivity 
for cutaneous pressure depends so largely upon the type of the 
instrument (including especially the area of the pressure stimulus 
and the manner of application) that the norms obtained with other 
instruments can not be assumed to hold good for the present form 
of balance. Jastrow's results indicate a constant of approximately 
1/15, which is nearly equal to that for lifted weights. Merkel 
similarly, reports 1/14 for his pressure balance, though Griffing 
believes that so fine a capacity as this must be attributed to the 
presence of a "muscular reaction of the finger." With a standard 
of 100 g. applied to the palm of the left hand, Miss Thompson found 
limens ranging from 4 to 20 g. 

(2) Dependence on the standard pressure. The limen for the same 
S, with the same instrument and method, is constant, at least for 
stimuli between 50 and 2000 g. (Weber's Law). 

(3) Dependence on the area of stimulation. According to Kiilpe 
(6, p. 160), the limen is 1/lQ to 1/20 with an area of contact 1 mm. 
in diameter, but rises to from 1/13 to 1/16 with an area of con- 
tact 7 mm. in diameter.- Griffing, however, declares that "the 
area of stimulation does not, on the whole, affect the accuracy of 
discrimination for weights, but individual peculiarities appear in 
the results obtained." 

(4) '^Practise seems to aid discrimination at places not accus- 
tomed to pressure stimuli" (Griffing). 

(5) There is no constant sex difference (Dehn, 2, and Thompson, 
9). 

(6) Dependence on length of interval. Accuracy of discrimination 
does not vary appreciably when the interval between application 

' If it were not for the awkwardness of the position, it would, perhaps, be 
better to insert the finger volar side uppermost, in order more certainly to 
ensure against this movement of reaction in unreliable »S"s. 

^ The tips of the author's balance are 8 mm. in diameter. 



198 SENSOEY CAPACITY 

of the t^vo stimuli is prolonged to 10 sec. (Griffing) or even to 30 
sec. (Weber). 

(7) Dependence on place stimulated. For weights of 100 g. or 
more, there is no appreciable difference in the discrimination of 
pressure on the palm of the hand, back of the hand, and the volar 
side of the index finger, though the last is probably more sensitive 
for very light weights (Griffing). 

(8) Constant error. Most S's show a tendency, frequently a 
marked tendency, to overestimate the second weight, i. e., to judge 
it to be heavier (Griffing). 

(9) Direct judgments. The impression of the standard stimulus 
not infrequently becomes so clear that it is carried over from one 
trial to another, so that, at least with large stimulus-differences, S 
may pass judgment when the first pressure is applied. 

REFERENCES 

(1) T. L. Bolton and Donna L. Withey, On the relation of muscle sense to 
pressure sense, in Nebraska Univ. Studies, 7: No. 2, April, 1907, 175-195. 

(2) W. Dehn, Vergleichende Prufung iiber den Haut- und Geschmack- 
Sinn bei Mannern u. Frauen verschiedener Stande, Dorpat, 1894. 

(3) J. A. Gilbert, Researches upon school children and college students, 
in Iowa S., 1: 1897, 1-39. 

(4) H. Griffing, On sensations from pressure and impact, in P. R. M. S., i : 
1895, No. 1, pp. 88. (Also Columbia Univ.Contr. to Phil. Psych, and Educ, 
iv.) Summarized in P. R., 2: 1895, 125-130. 

(5) J. Jastrow, On the pressure sense, in A. J. P., 3: 1890, 54-6. 

(6) O. Kxilpe, Outlines of psychology, Eng. tr., London, 1895. 

(7) J. Merkel, Die Abhangigkeit zwischen Reiz. u. Empfindung (II), in 
Ph.S., 5: 1889, 245. 

(8) E. C. Sanford, A course in experimental psychology, Boston, 1895 
and 1898. Pp. 449. 

(9) Helen B. Thompson, The mental traits of sex, Chicago, 1903. Pp. 
188. 

(10) E. B. Titchener, Experimental psychology, vol. ii., Quantitative ex- 
periments, N. Y., 1905. 

(11) G. M. Whipple, New instruments for testing discrimination of bright- 
ness and of pressure and sensitivity to pain, in J. E. P., 1: 1910, 101-106. 

TEST 22. 

Sensitivity to pain. — The determination of the threshold or hmen 
for pain has been conducted for the usual comparative purposes. 



TEST 22: SENSITIVITY TO PAIN 199 

but it has had, in addition, a peculiar interest for some investigators, 
because it has been assumed that the Hmen varies in a character- 
istic manner with sociological status. 

For the determination of the pain limen, use has been made both 
of electrical and of mechanical stimulation. Electrical stimulation 
(induction-coil current) has been employed chiefly by the Italian 
criminologists: pressure stimulation (upon the temple, palm, or 
finger-tip) has been employed almost exclusively by more recent 
investigators, and to this form of test our attention will be chiefly 
confined. 

The value of the conclusions that have been so far reached from 
the use of pain tests is minimized by the difficulties, not always 
clearly realized, which appear in their administration. These dif- 
ficulties, like those of most functional tests, arise primarily from 
the presence of a number of variable factors. The most important 
of these factors are: (1) dependence of the limen upon S's ability 
to keep pain distinct both from strong pressure and from simple 
discomfort, (2) dependence upon the rate of application of the stim- 
ulus, including the length of time elapsing between successive appli- 
cations, (3) dependence upon the place of stimulation, (4) depend- 
ence upon the area of the stimulus, (5) dependence upon 
the general condition and attitude of »S, his ''good- will, "degree of 
fatigue, amount of practise, etc., (6) dependence upon individual 
constitutional differences in sensitivity, including sex, age, etc. 
This last is, of course, the particular dependence sought for ir the 
results; the others, then, constitute disturbing factors and must, 
accordingly, be eliminated or at least eva'uated. Proofs of these 
several dependences are given below in the discussion of results, 
but the first and second of them demand consideration here because 
they determine the choice of apparatus and of method. 

(1) The dependence upon »S's judgment as to what constitutes pain has 
been recognized by most investigators as the primary source of difficulty in 
this test. It is undoubtedly true that pain is a specific sensory quality, dis- 
tinct from pressure and distinct from unpleasantness; yet it appears equally 
true that it is often difficult, even for a practised >S, to disentangle from his 
experience the three elements — cutaneous pressure, cutaneous pain, and 
discomfort. Children, to say the least, are not always competent to make 
such a differentiation, at least with the method of procedure that has com- 
monly been followed. 



200 SENSORY CAPACITY 

To meet this difficulty, some ^'s have instructed their S's to wait for the 
distinct appearance of pain; others have asked them to report the first 
appearance of discomfort — an affective experience that might, or might not, 
be accompanied by pain, and which can thus scarcely be regarded as a 
rational index of the real pain limen. Thus MacDonald says (13, 14) : "As 
soon as the subject feels the pressure to be in the least disagreeable, the 
amount of pressure is read from the scale .... The subject some- 
times hesitates to say just when the pressure becomes the least disagreeable, 
but this is part of the experiment (!). The idea is to approximate as near as 
possible to the threshold of pain." Griffing, however, thinks that there is 
little liability to error from this source: "It is very easy to tell," he says 
"when the pressure begins to be uncomfortable, and the 'imagination' does 
not .seem to be a disturbing factor. Indeed, the pain seems often to come 
with greater [great?] suddenness." We may wonder, then, why he says in 
the preceding paragraph: "The observers were asked to speak when the 
instrument began to hurt at all or to be uncomfortable ; for it was found that 
individuals differed as to what they called 'pain.' " Perusal of the literature 
makes it evident, as these instances illustrate, that some E's have been 
measuring a ''discomfort" limen, other a ''pain" limen: doubtless, in either 
case, some »S's reported ''discomfort," while others reported real ''pain." 

Yet again, it appears that schoolboys have sometimes understood tlje test 
to be a measure of their endurance of pain, and have manfully asserted : "It 
doesn't hurt yet" when the pain limen has long been exceeded. 

This difficulty of identification of the pain consciousness can not be wholly 
avoided, but it may be met, in part by giving S a clear account of the experi- 
ence he is to report as pain, in part, especially in doubtful cases, by repeat- 
ing the test, and in part by comparison of the results of a given S with the 
established norms for individuals of his age, sex, and type. 

(2) Unless the rate of application of the pressure is constant from test to 
test, there is introduced a serious variable error. Roughly speaking, the 
limen will be higher if the pressure is applied rapidly, lower if it is applied 
slowly. In the use of the ordinary type of pain-tester, e. g., of Cattell's (see 
14, p. 1161) or of MacDonald's (12 and 14, pp. 1155-6) algometer, the rate of 
application of pressure is difficult to control; moreover, the rate has never 
been standardized, so that different investigators have followed different 
rates. ^ The chief merit of the pain-balance, or balance-algometer, as 
employed by Gilbert or as prescribed in the present test, consists in the guar- 
antee that it affords of a rate of pressure increase that shall be uniform from 
step to step during each trial and from trial to trial. 

Again, the time interval between successive trials must be standardized. 
If a given region, say the right temple, has been tested, its sensitivity is 



^ In illustration, Griffing applied pressure with the Cattell algometer at 
the rate of 1.4 kg. per sec, whereas Gilbert applied pressure with his own 
instrument at the rate of 50 g. per sec, or only ^V as fast. 



TEST 22: SENSITIVITY TO PAIN 201 

increased for some time thereafter, yet some investigators have not hesi- 
tated to make a series of 5 or 6 tests upon the same spot in immediate succes- 
sion. On the other hand, if a given region be subjected to daily tests for 
several weeks, its sensitivity becomes reduced by a process of inurement. 
It is clear that both of these sources of error must be avoided in the deter- 
mination of the limen. 

The remaining sources of error are fully illustrated below, and are 
intelligible without further discussion. When all precautions have 
been taken, it is probable, however, that the results of this test will 
)je more variable and less reliable than those of other psychophysi- 
cal tests. ^ 

Apparatus. — The author's (20) pressure-pain balance (Fig. 47). 
Cardboard screen with suitable supports. Seconds' pendulum 
(Fig, 21) or other device for time-control. A low table. [Tele- 
graph sounder (Fig. 26), battery and wire.] 

Preliminaries. — Arrange the instrument and screen as in Test 
21. Place the pendulum within easy range of vision, or, since the 
time-relations are so important, convert it into an auditory signal 
by the use of the telegraph sounder and battery (preferably ad- 
justed to give a rather faint click). 

Method. — Seat S comfortably so that his hand lies upon the 
hand-rest with his finger-tip between the pressure-tips of the instru- 
ment, as described in Test 21. Give him the following inscruc- 
tions: "I want to measure your sensitiveness to pain. There is 
nothing for you to be afraid of, as I will stop the moment you tell 
me that you notice any pain. I shall add these weights, one after 
the other, on the end of this bar, and I want you simply to notice 
what you feel in your finger-tip. The pressure will grow stronger, 
bit by bit. It will, perhaps, feel uncomfortable after a time, but 
never mind that. Wait for the first moment when it really hurts, 
when you feel a stinging, sore feeling, or a real ache. Do you under- 
stand what I mean? I don't want to know how much pain you can 
'stand' without crying out; I don't want to know when it is simply 

1 The comments just given make it evident that MacDonald's algometer 
and Cattell's algometer are inadequate instruments. It follows that the 
results published by Griffing, Wissler, Swift, MacDonald, and Miss Carman 
are of doubtful value. Gilbert's results, though obtained by a better instru- 
ment, are more uneven than those of any other of the tests that he under- 
took and, on account of the slow rate of application that he used, are not 
directly comparable with those obtained by the method outlined below. 



202 SENSORY CAPACITY 

uncomfortable; I want to know when yoii first notice what you 
would call actual pain." 

Throw the release-lever up to the left, so that the support beneath 
the balance-beam is permanently depressed: this makes possible 
a continuous, but cumulative pressure upon the finger. 

Apply one of the large brass disc-weights, marked B-200 g., ever}- 
2 sec. These discs are placed, without jar, upon the pin marked i^, 
at the outer end of the beam. Continue application until S reports 
pain, then immediatelj' remove the pressure. The total weight on 
the beam measures >S's pain limen. 

Repeat the test with the left forefinger. 

Variations of Method. — (1) Test other fingers of both hands. 

(2) Apply the stimulus weights at a slower rate, say once in 4 
sec, and note the effect upon the limen. 

(3) Substitute a series of pressures for the cumulative, continu- 
ous pressure, by using the release-lever as in Test 21, and applying 
the pressure for 1 sec. only, after each weight is added. 

Results. — (1) The short series of tests available with the pres- 
sure-pain balance thus far has shown that, with adults, the pain 
limen may be expected to lie between 1600 and 2400 g., when the 
method of cumulative pressure is employed. 

(2) Dependence on rate of application, (a) "The rate at which 
pressure is added influences greatly the amount that is required to 
produce pain" (Gilbert). 

(b) Immediate or close repetition of stimulation causes in- 
creased sensitivity, but continued practise for several weeks appears 
to reduce it (Griffing, 8) . 

(3) Dependence on nature of stinndus. Sensitivity to pain pro- 
duced by electrical stimulation bears no noticeable relation to that 
produced in the same person by pressure stimulation (Griffing, 7). 

(4) Dependence on the area, of the stinndus. ' ' The pain threshold 
increases with the area of stimulation in an approximately logarith- 
mic proportion " (GriflSng, 8). Thus, when Cattell's algometer was 
applied to the palm of the hand, areas of 10, 30, 90 and 270 sq. mm. 
were correlated with limens of 1.4, 2.8, 4.4, and 6.6 kg., respec- 
tively.^ 

' The area of the pressure tip in the author's balance is approximately 
50 sq. nam. 



TEST 22: SENSITIVITY TO PAIN 203 

(5) Dependence on region. The regions of the body most sensi- 
tive to pain (from pressure stimulation) are those over the frontal 
and temporal bones, while the heel, the back, and the muscular 
regions of the leg and the hand are distinctly less sensitive. Illus- 
trative limens o])tained by Griffing are : 

KG. KG. 

Top of head =1.8 Right thigh, ventral surface = 4.3 

P'orehead =1.3 Left hand, volar side =6.2 

Right temple ± 1.0 Right heel, plantar side = 7.0 

Left temple =1.3 Back =8.0 

These differences seem "to depend largely upon the thickness of 
the skin and the extent of the subcutaneous tissues." The left side 
of the body is in general somewhat more sensitive than the right. 

(6) Dependence on sex. Gilbert (6), MacDonald, Dehn (4), 
Carman (2), Swift (16), and Wissler (21) agree that women are 
more sensitive to pain than are men. Thompson (17) agrees to this 
generalization, but adds that there are more men than women with 
very low thresholds, i.e., that there is greater variability in men. 
Ottolenghi (15) and Lombroso (10), on the other hand, state that 
(with electrical stimulation) women are markedly less sensitive 
than men. 

The latter authority believes that this result is confirmed by the experi . 
ence of surgeons, who find that women possess greater endurance of pain 
the popular opinion that women are more sensitive to pain is due, in his view- 
to the greater tendency of women to express feelings of pain by tears or other- 
wise; he also believes that their greater longevity may be due partly to their 
inferior susceptibility to pain. 

Typical results are those of Wissler and of Gilbert: the former 
publishes the following averages (Cattell algometer on the ball of 
the right thumb); college men, 5.9 kg.; college women, 2.4 kg. • 
Gilbert finds that the average difference between boys and girls is 
about 400 g., and that this difference increases with age, until at 18 
or 19 it becomes over 1 kg. (See Table 28.) 

(7) Dependence on age. Sensitivity to pain, in general, de- 
creases with age up to 18 or 19 years, and is thenceforth approxi- 
mately stationary, but Carman and MacDonald both find irregu- 
larities near the period of puberty, and Wissler finds Seniors mofe 



204 SENSORY CAPACITY 

sensitive than Freshmen (as a class) . It is probable that the gen- 
eral result is disturbed by a tendency on the part of younger chil- 
dren to shrink from the test and to report discomfort rather than 
pain. Gilbert's results are embodied in Table 28.^ 

TABLE 28 
Faitt Limen, in ky., for about 60 Boys and 50 Girls oj' each Age (Gilbert) 



10 11 12 13 I 14 I 15 I 16 17 j 18 



I ! i I ^ ' : I I I 
Boys 1.261.381.701.691.672.072.002.05:2.132.352.702.752.85 



Girls 1.150.931. 181. 36il. 451. 561. 461. 701. 821. 77|1. 85 



1.931.80 



Average 1.211.161.441.531.561.821.731.5 



1.982.062.282.342.33 



(8) The range of individual difference is large in the pain test. 
Gilbert, for example, found that the mean variation for his groups 
of children ranged from 330 to 820 g. 

(9) Dependence on fatigue. Swift (16) concludes that fatigue 
increases sensitivity to pain, especially in the case of younger pupils 
ai d of girls, because it lowers the tone and increases the irritability 
of the whole system.^ Essentially similar results are reported by 
Vannod (18) and by Vaschide (19). The former employed an 
instrument ('algesiometer') analogous to v. Frey's ' hair-esthesi- 
ometer,' and found that the pressure needed to produce pain fell 
from 45 g. at 8 a.m. to 39 g. at 10 a.m., and to 29 g. at 12 m., under 
the influence of school work. The latter concluded that pain tests 
warranted him in stating (1) that mathematics and ancient lan- 
guages possess an especially high fatigue-value, (2) that written 
exercises in the form of tests produce intense intellectual fatigue, 
(3) that afternoon is much more fatiguing than forenoon instruc- 
tion, and (4) that a forenoon spent outside of the school permits 

' [t should be remembered, again, that Gilbert used a very slow rate of 
application, so that his results may not be comparable with those obtained 
hy the methods we have prescribed. 

^ This conclusion is based upon tests before and after a 10 days' vacation 
in which the "physical condition" was determined by a dynamometer — 
a method already shown to be of doubtful value (Tests 6 and 9). There is no 
evidence to indicate that check-tests were made to determine the range 
of variations that might have appeared under constant work-conditions. 



TEST 22: SENSITIVITY TO PAIN 205 

a return, in most cases, to normal sensitivity. On the other hand, 
Binet (1), who used an adaptation of Blocq's sphygmometer, has 
come to diametrically opposite conclusions, and asserts that the 
effect of fatigue is to reduce, not to heighten, pain sensitivity. 

(10) Dependence on mental ability. The relation of the pain 
limen to mental abilitj is not clear. Carman found that bright 
hoys (teacher's estimate) were more sensitive than dull boys: Swift 
confirmed this by contrasting the best with the poorest fifth of a 
class, and attributes the result to the more delicate nervoiis organi- 
zation of bright children. MacDonald, however, says "there is no 
I ecessary relation between intellectual development and pain sen- 
sitiveness." "Obtuseness to pain seems to be due more to hardi- 
hood in early life." 

A curious and somewhat dubious correlation unearthed by Miss 
Carman is that boys and girls who are especially dull in mathemat- 
ics are more sensitive on the right than on the left temple. 

(11) Dependence on sociological condition, (a) Similarly un- 
convincing is the series of conclusions in which MacDonald (11, 13, 
1 4) summarizes his correlations between pain sensitivity and socio- 
logical condition ; e.g., girls in private schools, who are generally of 
wealthy parents, are more sensitive than girls in public schools; 
university women are more sensitive than washerwomen, but less 
sensitive than business women; self-educated women are more sen- 
sitive than business or university women (owing, perhaps, to over- 
taxing their nervous systems in the unequal struggle for an educa- 
tion); the non-laboring classes are more sensitive than the laboring 
classes, etc.^ 

(b) The study of the pain sensitivity of the criminal is a specific 
sociological problem that has attracted much attention since the 
concept of the 'criminal type,' or of the 'instinctive criminal,' 
was introduced by Lombroso and his school. It has been generally 
stated that the typical criminal is distinctly less sensitive to pain 
than the average normal man, and it has frequently been added that 
the norrn^l insensibility of the criminal is to be largely attributed to 

' The measurements from which these conclusions are drawn were made 
1)}^ different investigators, by an unreliable method, and have been assem- 
bled apparently by mere comparison of averages and with no attempt 
to determine the limit of error; they might, or might not, be confirmed by 
more exact methods. 



206 SENSORY CAPACITY 

this bodily insensibility. These statements are based upon certain 
experimental tests and upon common observations of the hardi- 
hood and general obtusity of the 'typical criminal.' Nevertheless, 
recent pain measurements indicate that the generalization is too 
sweeping, and that numerous exceptions occur. It may even be 
doubted whether the existence of a distinct criminal type has been 
satisfactorily established. 

A general summary of the pain sensitivity of criminals is given by Ellis 
(5, Section 8). The inadequacy of the algometer test as applied to crim- 
inals is discussed briefly by Miss Kellor. A typical exception to the gen- 
eral belief is found in Dawson's conclusion (3) that normal children are less 
sensitive to pain than delinquent children, probably because many of the 
delinquents were of neurotic type. 

(12) Miscellaneous correlations reported by Miss Carman are: 
boys with light hair and eyes are less sensitive than boys with dark 
hair and eyes. First-born are more sensitive than second-born 
boys, and the latter than later-born brothers : the same is true of 
girls, save on the right temple (!). These conclusions are subject 
to obvious criticism. 

REFERENCES 

(1) A. Binet, Recherches sur la fatigue intellectuelle scolaire et la mesure 
qui pent en etre faite au moyen de I'esthesiometre, in A. P., 11: 1905, 1-37, 
especially 32 ff. 

(2) Ada Carman, Pain and strength measurements of 1507 school children 
in Saginaw, Michigan, in A. J. P., 10: 1899, 392-8. 

(3) G. E. Dawson, A study in youthful degeneracy, in Pd. S., 4: 1896, 221- 
258. 

(4) W. Dehn, Vergleichende Prlifung liber den Haut- und Geschmack- 
Sinn bei Mannern u. Frauen verschiedener Stande, Dorpat, 1894. 

(5) H. Ellis, The criminal, 3ded., London, 1907. 

(6) J. A. Gilbert, Researches upon school children and college students, 
in lowaS., 1: 1897, 1-39. 

(7) H. Griffing, On individual sensitivity to pain, in P. R., 3: 1896, 412-5. 

(8) H. Griffing, On sensations from pressure and impact, in P. R. M. S., 
1: 1895, No. 1. Pp. 88 (also Columbia Univ. Contr. to Phil., Psych, and 
Educ, 4). Summarized in P. R., 2: 1895, 125-130. 

(9) Frances Kellor, Experimental sociology, N. Y., 1901. Pp. 316. 

(10) C. Lombroso, The sensibility of women, brief report in Mind, n.s. 1 : 
1892, 582. 



TEST 23: ESTHESIOMETRIC INDEX 207 

(11) A. MacDonald, Sensibility to pain by pressure in the hands of indi- 
viduals of different classes, sexes and nationalities, in A. J. P., 6: 1895, 621-2. 

(12) A. MacDonald, A temporal algometer, in P. R. 5: 1898, 408-9. 

(13) A. MacDonald, Further measurements of pain, in P. R., 6: 1899, 
168-9. 

(14) A. MacDonald, Experimental study of children, etc., reprint chs. 21 
and 25 of U. S., 1897-8, Washington, 1899. 

(15) S. Ottolenghi, La sensibilite de la femme, in Revue scient., Ser. 4, 
vols. 5: 395, and 6: 698. 

(16) E. Swift, Sensibility to pain, in A. J. P., 11: 1900, 312-7. 

(17) Helen B. Thompson, The mental traits of sex, Chicago, 1903. Pp. 
188. 

(18) Th. Vannod, La fatigue intellectuelle et son influence sur la sensi- 
hilito cutance, in Rev. med. de la Suisse Romande, 27: 1896, 21. 

(19) N. Vaschide, Les recherches experimentelles sur la fatigue intellec- 
tuelle, in Revue de philos., 5: 1905, 428. 

(20) G. M. Whipple, New instruments for testing discrimination of briglit- 
ness and of pressure and sensitivity to pain, in J. E. P., 1 : 1910, 101-106. 

(21) C. Wissler, The correlation of mental and physical tests, in P. R. M. 
S., 3: No. 6, 1901. Pp. 62. 

TEST 23 

Discrimination of dual cutaneous impressions : Esthesiometric 
index. — As long ago as 1834, E. H. Weber, a German physiologist, 
observed (50) that, if two punctiform pressures are applied simul- 
taneously to adjacent points on the skin, a single impression results, 
whereas, if the pressure points are applied at gradually increased 
distances, an extent can be discovered which is just sufficient to 
yield a perception of two points. Weber explored many regions of 
the skin and published extended tables of measurements of this dis- 
tance, which has since become known variously as the "limen for 
duality," or "doubleness," as the "esthesiometric index," the 
"space threshold," or even, less exactly, as the "index of delicacy of 
touch." 

On account of Weber's explanation of the phenomenon, which 
was in terms of the supposedly quasi-circular distribution of the 
end-organs of the sensory nerves, the experiment is often referred 
to as thetestof "sensory circles." Onaccountof thetypeof instru- 
ment employed, it is sometimes termed the "compass test." 

Since Weber's time the experiment has become a classic in psy- 
chology. Seemingly simple and definite, more careful examination 



208 SENSORY CAPACITY 

has revealed the fact that the determination of the esthesiometric 
index is in reahty unusually difficult, and that the factors which 
underlie the observer's judgment are surprisirgly varied and subtle. 

For differential psychology, the chief interest in the test is found 
in its use by criminologists to measure "general sensibility," and by 
several German investigators to measure the degree of fatigue of 
school children. Physicians, also, have employed it for diagnostic 
purposes, particularly in connection with pathological conditions of 
the spinal cord, and it has found special favor in the psychological 
laboratory, both for its intrinsic interest and for the illustration of 
various psychophysical methods. 

As in the case of other tests, the chief difficulty in the use of the 
esthesiometric test lies in the presence of numerous sources of error, 
which must be fully recognized and controlled if valid results are to 
be secured. In general, it may be said that the esthesiometric 
limen will depend upon (1) the instrument employed, (2) the region 
of the body tested, (3) the method of procedure, including the 
nature of the instructions, (4) the care with which E applies the 
stimulus and the actual pressure employed, (5) S's degree of fatigue, 
(6) *S's degree of practise, (7) S's abihty to attend to the impressions 
and to make accurate reports, especially in the 'critical region,' 
and (8) upon a number of other factors, such as >S's sex, age, the 
condition of the circulation in the region tested, etc. The manner 
in which these factors affect the index will be discussed below. 

The instrument employed may be extremely simple, e.g., the set 
of needles thrust through bits of cardboard, used by Binet in his 
earlier tests (2), or it may be very complicated and elaborate. 

In general, the development of the esthesiometer since Weber's time has 
been in the direction of greater complexity and delicacy, with a view of 
affording more adequate control of the separation of the points, of the simul- 
taneity of their application, and of the degree of pressure exerted. It is 
doubtful whether much of this elaboration is needful: objective equaliza- 
tion of the pressure does not insure subjective equalization, and a careful E 
is better able to apply the points simultaneously if he works with a rela- 
tively simple instrument. 

The instrument selected, an improved form of Jastrow's esthesiometer, 
possesses all the requisite features. For other models, consult Blazek (7), 
Binet (3, 4), and Washburn (48). The models of Ebbinghaus and v. Frey 
are figured in Zimmermann's catalog. Spearman's instrument is described 
in Sommer (38) and pictured in use in Schulze (33, p. 67). 



TEST 23: ESTHESIOMETRIC INDEX 



209 



Apparatus. — Jastrow's improved esthesiometer (Fig. 48). 
Cardboard screen and supports. Pillow or folded towel. 

Method. — (a) Preliminary practise. Seat S comfortably with 
his right ^^orearm laid horizontally, volar side uppermost, upon a 
small pillow or folded towel, with the clothing arranged to expose 
the forearm from elbow to wrist, without impeding the circulation 
at the elbow. 




IMPROVED ESTHESIOMETER. 



Arrange the screen to cut off from S the view of his forearm and 
of the instrument. 

Devote from 2 to 5 min. to a preliminary practise series in order 
to familiarize S with the test, particularly with the perception of 
one and of two points. 

Id struct all <S's, in the same words, substantially as follows : "I'm 
going to touch your arm with points, something like pencil-points. 
They won't hurt you at all .*^ You are to give careful attention to 
what you feel, and tell me if you think I'm touching you with one 
point or with two points. You will have to watch very carefully. 
If you feel only onejpoint, say "one:" if you feel two, say "two." 

Begin with a distinctly supraliminal distance, say 90 mm. After 



210 SENSORY CAPACITY 

a warning 'ready' signal, bring the instrument down perpendicu- 
larly upon the middle of the forearm, parallel with its longitudinal 
axis, in such a manner that both points make contact simulta- 
neously,^ and rest by their own weight upon the skin, as the holder 
is allowed to slide one or two cm. down the stem of the instrument. 
The several applications should be uniform in duration — about 1.5 
sec. 

Next apply a single point, then two points at 80 mm., and so on, 
giving sometimes one point ana sometimes two points, of varying 
distances and in irregular order. Leave an interval of 7 to 10 sec. 
between trials to allow the preceding sensory disturbance to die 
away. Work as nearly as possible in the same region, but to avoid 
local fatigue, do not seek to apply the compass upon exactly the 
same spots at each trial. Avoid contact with hairs, which set up 
tickling sensatioiss, or pressure upon projecting veins or tendons, 
which will be of a character dissimilar to the normal contact. 

This practise should help S to be familiar with, and to distinguish the 
'feels' of one point and two points. It will be found that some *S's will, 
nevertheless, occasionally answer "two" when but one point is given. This 
is the not uncommon Vexirfehler, or esthesiometric paradox, which is well 
recognized as a source of difficulty in esthesiometry. If it proves persistent, 
it will probably be impossible to determine an exact limen with that partic- 
ular S. To avoid it, E may allow S to look at the instrument when one point 
is resting on the skin and he has just announced "two." Sometimes young 
.S's, who have caught sight of the instrument, may, with childish logic, con- 
clude that there must always be two points because there are two on the 
instrument. 

Children who display timidity must be encouraged to adopt a more favor- 
able attitude toward the test. 

(6) Test propel'. Allow S a short rest (during which his arm 
should be withdrawn from the somewhat constrained position); 
then resume the experiment in accordance vvith the general instruc- 
tions for discrimination work given at the beginning of the chapter. 
Proceed from a distinctly supraliminal distance toward the critical 
region until a distance is found that proves difficult for S to judge. 
Then give a series of 10 double contacts at that distance, but add 
to these, two or three single contacts for check tests. Make a 

' This is imperative because the limen for successive stimuli is only § 
to i that for simultaneous stimuli. 



TEST 23: ESTHESIOMETRIC INDEX 211 

record of the order used, and follow it for each S. If S makes 10 
correct judgments for the 10 double contacts, try another series 
with a lesser separation: if he makes but 5 or 6 correct jadgments, 
increase the separation. Seek a distance such that about 8 correct 
judgments in 10 are made, i.e., such that double contact is reported 
as double in 8 of 10 trials. The check tests should, of course, be 
judged "one," but if the paradoxical error does appear, E must 
either try a wider separation, or give up, for the time being, the 
attempt to find a definite limen. 

Variations of Method. — Test other regions of the body. Use 
a transverse application on the forearm. Compare the sensitivity 
before and after periods of rest or of fatiguing work. Test the 
acquisition of practise and its transfer to symmetrical and adjacent 
portions of the body. 

Results and Conclusions. ^ — (1) Dependence on sex. Wis- 
sler (51) could discover no sex differences in cutaneous discrimina- 
tion of dual pressure, but Miss Thompson (41), despite some 
acknowledged difficulties in the administration of her test, con- 
cludes that "women have a somewhat finer discrimination in the 
crosswise direction, and a decidedly finer discrimination in the 
lengthwise direction." Actual figures cited are 20 and 65 mm. "or 
women and 35 and 75 mm. for men, in the transverse and longitud- 
inal directions, respectively. 

(2) Dependence on age. There is fair agreement, especially 
among the earher investigators (see e.g., Czermak, 11) that chil- 
dren have a greater sensitivity than adults. Similarly, Wissler 
found Seniors inferior to themselves as Freshmen. In regions 
where the sensitivity is poor, the difference between children and 
adults is quite cUstinct, e.g., a limen of 67 mm. on the thigh of an 
adult in contrast to 35 mm. uj^on the same region in a boy of 12. 

The usual explanation that the child has a greater number of nerve endings 
within the same sized area is probably only a partial explanation, as it has 
been computed that the child's sensitivity is out of all proportion to the 
differences in dimensions here concerned. A contributory factor is doubt- 
less to be found in the fact that the child's skin is thinner and more tender, 
so that a given impact produces a sharper sensory experience. 



^ In reporting these results, it may be stated that many of them have been 
obtained by methods that are open to criticism, particularly in that suit- 
able precautions have been wanting to control or to eliminate the numerous 
disturbing factors already mentioned. 



212 SENSORY CAPACITY 

Griesbach (15), who found no difference between children from 
11 years up to 19, is practically the only investigator who has not 
found the child more sensitive than the adult, but Griesbach's fig- 
ures can not be accepted without misgivings. 

(3) Dependence on region, (a) Table 29, which is derived 
from Weber's original results, gives an idea of the topographic dis- 
tribution of sensitivity. 

TABLE 29 

Topography of Esthesiometric Sensitivity (Weber) 



LIMEN IN MM. ll 



Tip of the tongue 

Tip of the fingers 

Mucous membrane of the lips. 

End of the nose 

Cheek 



1.1 I Forehead 22.5 

2.2 j Back of hand | 31.5 
4.5 i Forearm 40.5 
6.7 Back 54.1 

11.2 I Thigh 67.6 



An empirical generalization, known as Vierordt's Law (45, p. 
298), summarizes these differences in sensitivity, especially of the 
limbs and head, by the statement that the delicacy of discrimination 
of two regions on the skin of a portion of the body that is moved as 
a whole is proportional to the average distance of these regions from 
their common axis of rotation.^ In illustration, if the discrimina- 
tive sensitivity of the tip of the shoulder (acromion) be taken at 
100, then that of the upper arm is 151, of the forearm 272, hand 
659, thumb 2417, middle finger 2582. 

(6) _ Van Biervliec (42), who asserts that in many sense-depart- 
ments the favored side of the body is superior to the other side by the 
fraction ^, publishes tables which indicate that the same constant 
applies in esthesiometry. 

(4) Dependence on time of day. A comparison of the sensi- 
tivity at different periods of the day, in the search for a diurnal 
rhythm, is, of course, complicated l)y the presence of fatigue (see the 

' Somewhat analogously, Krohn (25) cites an instance in which a man 
whose arm had been held immovable in a plaster cast for three months 
exhibited marked decrease of sensitivity of that arm shortly after the cast 
had been removed. 



TEST 23: ESTHESIOMETRIC INDEX 213 

following paragraph), and doubtless by individual differences as 
well. Schmey (32) believes sensitivity to be less at night than in 
the morning. Adsersen (1), however, asserts that sensitivity is 
lowest in the morning, begins to improve at about 11, reaches a 
maximum from 3 to 7, and thence decreases. By comparison, he 
shows that this rhythm coincides very closely with the diurnal 
curve of bodily temperature, and he therefore argues that the esthes- 
iometric fluctuations are indices of physiological changes common 
to the diurnal rhythm. Tawney's work (39), on the other hand, 
leads one to believe that the limen undergoes, in many *S's, such 
irregular fluctuations that it is impossible to find a limen that 
is constant for half an hour at a time. 

(5) Dependence on fatigue. The effect of fatigue upon the 
hmen forms the chief source of interest in connection with the 
esthesiometric test. Griesbach (15) was the first to make extended' 
use of the test in the examination of school children. His amaz- 
ingly uniform and definite results, wher taken at their face value, 
indicate unequivocally that the method is of value and importance 
in the detection of the fatigue induced by school work. They have, 
moreover, been confirmed more or less thoroughly by Binet (6b), 
Blazek (7), Bonoff (10), Heller, Schuyten (35), Vannod (44), and 
Wagner (47). On the other hand, they have been controverted 
with equal emphasis by Bolton (8, 9), Germann (13), Kraepelin (24), 
Leuba (25), and Ritter (30). Investigations of fatigue by means 
of the esthesiometric test have also been made of late by Ferrai in 
Italy, Sakaki (31) in Japan, Ley in Belgium, Michotte in Belgium, 
and Noikow (28) in Bulgaria.^ 

Griesbach argues that fatigue reduces the power of sustained attention' 
and that this in turn reduces the cutaneous sensitivity. He appears to 
believe that he is the first to have discovered this relation, but it may be 
noted that Weber, himself, had cautioned his readers to avoid fatigue if 
valid results were to be secured, that Schmey, in 1884, had demonstrated that 
the fatigue of the arm by calisthenic exercises reduced sensitivity, and that 
Stanley Hall (17), in 1879, had commented on the variability of the results 
obtained from Laura Bridgman, and had expressed the hope that "a curve 

1 For further discussion of the value of the method, consult Gineff (14), 
Meumann (27, vol. ii., 89-94, 107-110) and the recent monograph of Offner 
(29, 18-23). Griesbach's rejoinder to his critics (16) should also be con- 
sulted. 



2l4 SENSOKY CAPACITY 

of fatigue may be obtained by which some approximate comparison with the 
fatigue of a nerve-muscle preparation may be made." Griesbach worked 
on the glabella, cheek-bone, tip of the nose, under lip, ball of the thumb,and tip 
of the index-finger, and tested pupils before and after various kinds of school 
work, on Sundays, holidays, at the end of vacations, etc. A single example 
will suffice: a girl of 14 had a limen on the glabella of 5 mm. at 7 a.m., but 
this increased to 12.5 mm. at 12, noon, after a morning at school, whereas on 
Sunday her limen was but 3.5 mm. Griesbach concludes his meinoir with a 
strong plea against over-work, and asserts that no schoolboy can meet in full 
the demands of present-day higher education without endangering his health 
(15, p. 88). 

Blazek divides pupils into three types, (1) those who possess ability, who 
work industriously and attentively, and thus exhibit distinct and progres- 
sive fatigue curves, (2) those who work intermittently, and whose curve is 
therefore broken by recuperative periods, (3) those whose curve is approxi- 
mately a straight line. The fatigue curve, therefore, depends in the main 
upon the type of worker,but the individuality of the teacher and the subject- 
matter in hand are also determining influences. He concludes that more 
than half the pupils work irregularly and thus save themselves in part from 
over-work. He would recommend 4 subjects daily, of 45 min. each, with 15 
min. rest-periods between each subject. 

Wagner says that the Griesbach method is a valuable adjunct for the study 
of fatigue. Afternoon instruction is practically valueless pedagogically. 
Play and gymnastics are sources of fatigue to many pupils, and should be 
relegated to the close of instruction or to the afternoon. If the fatigue-value 
of mathematics be placed at 100, other subjects may be rated thus: Latin 
91, gymnastics 90, geography and history 85, French and German 82, nature- 
^tudy 80, drawing and religion 77. 

Binet summarizes the results obtained by himself, and by a group of teach- 
ers who worked under his direction, by declaring that ' ' intellectual fatigue is 
manifested by a reduction of sensitivity, measurable on the back of the hand : 
this reduction is revealed by fewer judgments of 'two' for smaller dis- 
tances (0.5 to 1.5 cm.), is more pronounced for girls than for boys, and is to 
be attributed to an actual reduction of tactual sensitivity itself, not to a mere 
relaxation of attention" (6 b, p. 29). It is to be noted, however, that this 
conclusion is based upon the 'lump' results obtained from groups of school 
children: analysis shows that, in some groups at least, less than half of the 
pupils (e.g., 31 of 75), gave evidence of fatigue in this way. Moreover, 
Binet's method of distinguishing between the effects of lessened sensitivity 
and of lessened attention is open to debate. 

Schuyten at first condemned the esthesiometric method (34), but later 
(35) he found to his surprise that it worked satisfactorily. He used groups 
of 5 selected pupils. 

Ritter tested himself at intervals for two years, but could get no evidence 
of fatigue by the esthesiometer. 



TEST 23: ESTHESIOMETRIC INDEX 215 

Bolton says the limeii is so hard to determine that it can not be satisfac- 
torily accomplished in a single sitting. In his tests, severe mental work of 
two hours duration did not produce a measurable change in the index. 

Germann, after making 2450 trials on a single.5, could not discover any 
relation between fatigue and the limen. 

Leuba admits that fatigue affects the limen, but says that it is only one of 
a great many factors. He was unable to draw any general inductions con- 
cerning fatigue, even when the results for three days of severe mental work 
were contrasted with those for three days of rest. 

Meumann (27, vol. 2, 90 fT.), similarly, admits that the tendency of fatigue 
is to heighten the limen, but protests vigorously that the relation is but 
indirect, and so complicated by numerous little-known factors that the 
numerical expression of shifts in the limen can in no wise be regarded as a 
measure of fatigue. ("Wir haben in der Erhohung der Raumschwelle durch 
die Ermtidung nur ein objectives Symptom derselben, aber keine Messung.") 

Kraepelin, however, declares flatly that investigations that embody meas- 
urements of fatigue by the use of the esthesiometer are "all in the air" 
(stehen einf ach in der Luf t ) , and are nothing but the unintentional expression 
of the preconceived opinions of the investigators. 

(6) Dependence on practise. The effect of practise was studied 
by Czermak (11), as early as 1855, in his investigation of the sen- 
sitivity of the bhnd, was measured more carefully by Volkmann 
(46), and confirmed later in particular by Dresslar (12). From 
these investigations, it would appear that the practise-effect is vis- 
ible within two hours, and may be pushed to unexpected lengths 
by continued work; thus, Dresslar reports one S, who started with 
a limen of 29 mm., reduced this to 21 mm. in the first week, to 10 
mm. the second week, 5.5 mm. the third week, and 2.8 mm. the 
fourth week — a net reduction, then, to approximately jo of the 
original figure. This practise-effect is, however, rapidly lost, being 
reduced very definitely within 8 days and completely lost within 
a month. The practise-effect is said to appear much more rapidly 
on fingers, hands, and other exposed parts, than on the back and 
other relatively inaccessible and immobile regions. Both Volk- 
man and Dresslar submit evidence to show that this 'education' is 
subject to transfer to symmetrical regions, though rot to regions 
adjacent to the one on which it was effected. 

In seeking an explanation for the effect of practise, we are met with the 
fact that other investigators have not confirmed the results just cited. 
Camerer, in his lengthy series, did not find such extensive practise-effects 



216 • SENSORY CAPACITY 

Tawney (40) found his work so vitiated by Vexirfehler and by auto-sugges- 
tion in general that he was unable, for some S's, to establish any constant 
limen. Both Tawney and Henri (18, b) deny that the influence of practise, 
when established, is confined to symmetrical regions of the body. Solo- 
mons (37) asserts that the practise-effect is rapid if S is informed of his 
errors, but practically non-existent if he is not — a principle, which, if con- 
firmed, may explain the disagreements just cited. 

The explanation of the process of 'education' in this test is found by some 
writers to lie in certain peripheral processes— not necessarily in anatomical, 
since the practise is too rapid to admit of that, but rather in local physio- 
logical, processes. Others, e.g., Judd (21) and Solomons (37), believe that 
the education is essentially a 'central,' or psychological, process — an im- 
provement in judgment due to the learning of new associations. 

The low threshold of the blind, reported by Goltz, Gartner, Heller, Miss 
Washburn (49), Hall (17), Jastrow (10), and others, is to be deemed a special 
example of practise, and does not imply the presence of exceptional sensi- 
tivity or special peripheral delicacy. Helen Keller (20) has a limen of 1.5 
mm. on the tip of the left forefinger, and 3-4 mm. on the palm of the hand, 
which is smaller than that of the average S. Laura Bridgman (17) is cred- 
ited with a limen of 0.7 mm. on the right forefinger, and her general sensi- 
tivity of touch, according to Hall, was "from two to three times as great as 
that of an ordinary person." 

(7) Dependence on expectation. An importaDt feature of esthes- 
iometry has been emphasized by the work of Solomons and of Taw- 
ney, both in the latter 's own investigation (40) and in that under- 
taken with Henri (19). These writers have shown thac expecta- 
tion or suggestion plays a preponderant role in esthesiometry. By 
arranging the conditions suitably, they were able, for example, to 
induce practised and reliable S's to judge, with considerable uri- 
formity, "one" when two points were given, and "two" when one 
point was given.^ 

It is of interest herewith to no^e that the esthesiometric paradox 
often appears more frequently as practise continues, and is more 
likely to appear in tests of adults than in tests of children. 

(8) Dependence on circulation of the blood. The condition of the 
circulation in the region under test affects the limen. It appears 

f ' These observations, which'might be repeated in many other fields, show 
how essential it is to work methodically and under constant conditions. 
The extent to which »S's discrimination is affected by his attitude toward 
the experiment, and by his manner of judging in general, has led Binet to 
declare (5) that the "compass test" measures "tactual intelligence" 
rather than the fineness of touch itself. 



TEST 23: ESTHESIOMETRIC INDEX 217 

from the studies of Brown-Sequard, Schmey, and others, that arte- 
rial hyperemia increases cutaneous sensitivity, whereas aremia, or 
venous hyperemia, or decided cold, reduces sensitivity. Excessive 
stretching of the skin decreases sensitivity, as does the use of nar- 
cotics. 

(9) Dependence on intelligence, (a) There is no clear relation 
between general intelligence and the esthesiometric Hmer, The 
rather crude test of Wissler (45) revealed no correlation wiuh the 
class standing of university students. Binet (2) found hisintel- 
ligeni superior to his unintelligent group afc the first trial, but the 
difference soon lessened as the boys became adapted lo the test. 
V"an Biervliet (43) used the compass test to secure a measure of 
intelligence, not by the limen itself, but by its mean variation, on 
the assumption that this latter measure is, in almost any test, the 
real index of intelligent work. His figures give the 10 most intel- 
ligent of 300 university students an index of 17.7, and the 10 least 
intelligent an index of 27.6. His index, however, as Binet (6 a) has 
pointed out, is a rather dubious device. 

(6) As might be expected, the use of the test for the examina- 
tion of abnormal children, criminals, truants, etc., is beset with diffi- 
culty, because it exacts prolonged, sustained attention and interest 
(Kellor, 22; Kelly, 23). Simon (36) was unable to test the lowest 
grade of children in a school for the feeble-minded, but obtained 
results from the less defective types which indicated that their 
sensitivity was less than that of normal children. Whether the 
difference is reducible to differences in cutaneous sensitivity itself, 
or to differences in ability to control the attention and understand 
directions, is not clear. 

REFERENCES 

(1) H. Adsersen, Eine aesthesiometrische Untersuchumg, in Z. S.. 27: 
1904, 540-3. 

(2) A. Binet, Attention at adaptation, in A. P., 6: 1899 (1900), 248-404. 

(3) A. Binet, (a) Un nouvel esthesiometre, in A. P., 7: 1800 (1901), 231-9; 
(6) Technique de I'esthesiometre, 240-8. 

(4) A. Binet, La mesure de la sensibilite, in A. P., 9: 1902 (1903), 79-128. 
Also five other articles on esthesiometry, pp. 129-252. 

(5) A. Binet, De la sensation h I'intelligence, in Rev. philos., 56: 1903, 
450-467, and 592-618. 



218 SENSORY CAPACITY 

(6) A. Binet, (a) A propos de la mesure de I'intelligence, in A. P., 11: 
1905, 69-82. (b) Recherches sur la fatigue intellectuelle scolaire et la mesure 
qui peut en etre faite au moyen de I'esthesiometre, do., 1-37. 

(7) B. Blazek, Ermiidungsmessen mit dem Federaesthesiometer an Schti- 
lern des Franz-Joseph-Gymnasiums in Lemberg, in Z. P. P., 1: 1899, 311-325. 

(8) T. Bolton, The reliability of certain methods for measuring the degree 
of fatigue in school children, in P. R., 7: 1900, 136-7. 

(9) T. Bolton, Ueber die Beziehungen zwischen Ermiidung, Raumsinn 
der Haut und Muskelleistung, in P. A., 4: 1902, 175-234. 

(10) N. Bonoff, Etude medico-pedagogique sur Testhesiomctrie et la sim- 
ulation a I'ecole, in I. M. S. H., 4: 1907-8, 384-394. 

(11) J. N. Czermak, (a) Beitrage zur Physiologic des Tastsinnes, Wien., 
15: 1855, 466-520; (6) Weitere Beitrage, etc., ibid., 28: 577-600. 

(12) F. B. Dresslar, Studies in the psychology of touch, in A. J. P., 6: 
1894, 313-368. 

• (13) G. Germann, On the invalidity of the esthesiometric method as a 
measure of mental fatigue, in P. R., 6: 1899, 599-605. 

(14) D. Gineff, Prtifung der Methoden zur Messung geistiger Ermiidung, 
Zurich, 1899. Pp. 68. 

(15) H. Griesbach, Energetik u. Hygiene des Nerven-Systems in der 
Schule, Munich u. Leipzig, 1895. Pp. 97. Also published as Ueber Bezie- 
hungen zwischen geistiger Ermiidung u. Empfindungsvermogen der Haut, 
in Arch. f. Hygiene, 24: 124. 

(16) H. Griesbach, Weitere Untersuchungen iiber Beziehungen zwischen 
geistiger Ermudung u. Hautsensibilitat, in I. M. S. H., 1: 1905, 317-417. 

(17) G. S. Hall, Laura Bridgman, in Mind, 4: 1879, 149-172, especially 
160 ff. 

(18) V. Henri, (a) Revue generale sur le sens du lieu de la peau, in A. P., 
2: 1895 (1896), 295-362 (with bibliography). (6) Ueber die Raumwahrneh- 
mungen des Tastsinnes, Berlin, 1898. Pp. 228. (With extended bibliog- 
raphy). 

(19) V. Henri and G. Tawney, Ueber die Trugwahrnehmung zweier Punkte 
bei der Beriihrung eines Punktes der Haut, in Ph. S., 11: 1895, 394-405. 

(20) J. Jastrow, Psychological notes on Helen Keller, in P. R., 1: 1894, 
356-362. 

(21) C. Judd, Ueber Raumwahrnehmungen im Gebiete des Tastsinnes, in 
Ph. S., 12: 1896, 409-464. (Historical survey, 451-8). 

(22) Frances Kellor, Experimental sociology, N. Y., 1901. Pp. 316. 

(23) R. L. Kelly, Psychophysical tests of normal and abnormal children; 
a comparative study, in P. R., 10: 1903, 345-372. 

(24) E. Kraepelin, Ueber Ermiidungsmessungen, in A. G. P., 1: 1903,9-30. 

(25) W. Krohn, Sensation-areas and movement, in P. R., 1: 1894. 280-1. 

(26) J. Leuba, On the validity of the Griesbach method of determining 
fatigue, in P. R., 6: 1899, 573-598. 

(27) E. Meumann, Vorlesungen zur Einfiihrung in die exp. Padagogik, 
Leipzig, 1907. 



TEST 23: ESTHESrOMETRIC INDEX 219 

(28) P. Noikow, Aesthesiometrische Ermiidungsmessungen, in I. M.S.H., 
4: 1907-8, 437-481. 

(29) M. Offner, Die geistige Ermiidung, Berlin, 1910. Pp. 88. 

(30) C. Ritter, Ermudiuigsmessungen, in Z. P., 24: 1900, 401-444. 

(31) Y. Sakaki, Ermiidungsmessungen in vier japanischen Schulen, in 
r. M. S. H., 1:1905,53-100. 

(32) Schmey, Ueber Modificationen der Tastempfindung, in DuBois- 
Reymond's Archiv. (Physiol.), 1884, 309-312. 

(33) R. Sohulze, Aus der Werkstatt d. exp. Psych, u. Padagogik, Leipzig, 
1909. Pp. 292. 

(34) M.-C. Schuyten, Sur les methodes de mensuration de la fatigue des 
ecoliers, in Ar. P., 2: 1903, 321-6. 

(35) M.-C. Schuyten, Comment doit-on mesurer la fatigue des ecoliers, 
in Ar. P., 4: 1904, 113-128. 

(36) T. Simon, L' interpretation des sensations tactiles chez les enfants 
arrieres, in A. P., 7: 1900 (1901), 536-558. 

(37) L. Solomons, Discrimination in cutaneous sensations, in P. R., 4: 
1897, 246-250. 

(38) R. Sommer, Ausstellung v. exp. psych. App. u. Methoden, 1904. 

(39) G. Tavvney, The perception of two points not the space-threshold, 
in P. R., 2: 1895, 585-593. 

(40) G. Tawney, Ueber die Wahrnehmung zweier Punkte mittelst des 
Tastsinnes, mit Riicksicht auf die Frage der Uebung, in Ph. S., 13: 1897, 
163-222. 

(41) Helen B. Thompson, The mental traits of sex, Chicago, 1903. Pp. 
188. 

(42) J. van Biervliet, L'asymetrie sensorielle, in Bull. Acad. Royale des 
Sciences, etc. de Belgique, 34: Serie 3, 1897, 326-366. 

(43) J. van Biervliet, La mesure de rintelligence, in Jour, de psych., 
1 : 1904, 225-235. 

(44) T. Vannod, (a) La fatigue intellectuelle et son influence sur la 
sensibilite cutanee, in Rev. Med. de la Suisse Romande, 17: 1897, 21. 
(6) La methode esthesiometrique pour la mensuration de la fatigue 
intellectuelle, in Rept. 1st Intern. Cong, on School Hygiene, Niirnberg, 
1904, vol. ii. 

(45) K. Vierordt, Ueber die Ursache verschiedenen Entwickelung des 
Ortssinnes der Haut, in Pfluger's Archiv, 2: 1869, 298-306. Also Die Abhang- 
igkeit der Ausbildung des Raumsinnes der Haut v.d. Beweglichkeit der 
Korperteile, in Zeits. f. Biol., 6: 1870. 

(46) A. Volkmann, Ueber den Einfluss der Uebung auf das Erkennen 
riiumlicher Distanzen, in Ber. d. Sachs. -Ges. d. Wiss., 10: 1858, math. phys. 
Abth., 38-69. 

(47) L. Wagner, Unterricht u. Ermiidungsmessungen an Schiilern des 
neuen Gymnasiums in Darmstadt, in S. Z., 1: 1898, Hft. 4, Pp. 134. 



220 SENSORY CAPACITY 

(48) Margaret Washburn, Some apparatus for cutaneous stimulation 
(with cut), in A. J. P., 6: 1894, 422-3. 

(49) Margaret Washburn, Ueber den Einfluss der Gesichtsassociationen 
auf die Raumwahrnehmungen der Haut, in Ph. S., 11: 1895, 190-225. 

(50) E. H. Weber, De pulsu, resorptione, auditu et tactu, Leipzig, 1834. 

(51) C. Wissler, The correlation of mental and physical tests, in P. R. M. 
S., 3: No. 6, 1901. Pp. 62. 



CHAPTER VII 

Tests of Attention and Perception 

The tests included in this chapter are those commonly assumed 
to measure such capacities as "power of observation," "quickness 
of perception," "range of attention," "mental grasp," etc./^hey 
are practically confined to the sphere of visual perception, and 
imply that this perception takes place under active attention: thus, 
in general, thej^ seek to determine the subject's capacity to per- 
ceive visual symbols when the conditions of perception are limited 
by short temporal persistence of the stimulus, or by other difficul- 
ties or complications that are intentionally introduced. ' 

It has been said that experimental psychology discovered atten- 
tion. Whether this be strictly true or not, every psychological 
experiment of necessity takes account of attention. And so, in 
every mental test that presupposes effort or concentration, we meas- 
ure the capacity under investigation, always as conditioned by the 
particular degree of attention manifested at the time. It follows 
that a fundamental presuppositior for the comparison of the results 
of such tests is that they shall all be secured under the same condi- 
tion of attention. In practise, we find that the best way to secure 
this constant degree of attention is always to exact the maximal 
degree. Yet, in so far as the capacity to attend does differ in dif- 
ferent individuals and in the same individual at different times, just 
so far our tests of various other capacities, such as discrimination, 
retention, and the like, are often felt to be measures of attention, 
quite as much as measures of these other capacities. 

Despite this fact, or perhaps on account of it, a direct measure or 
test of degree of attention is difficult to secure. In theory, since 
attention is a condition of consciousness in which certain constit- 
uent processes are clear and prominent, attention is directly meas- 
urable in terms of clearness. In practise, we must, in all proba- 
bility, content ourselves with an attempt to measure attention 



222 ATTENTION AND PERCEPTION 

indirectly, not by any single test, but by a series of tests, all of 
which exact maximal effort : even then, it must be recognized that 
we measure, not the process or condition of attention itself, but a 
product or concomitant of that condition.^ 

A fundamental source of difficulty in these tests of attention lies 
in the fact that, with repetition, or even with the progress of the first 
trial, the task assigned becomes progressively easier; a tendency 
toAvard automatism appears, and the tax on attention diminishes 
proportionately. 

TEST 24 

Range of visual attention. — In a single pulse' of attention only 
a small number of impressions can stand out clearly: the area or 
span of consciousness is definitely limited. In the sphere of vision, 
we find that if we give but a single glance at any heterogeneous col- 
lection of objects, such as the goods displayed in a store-window, or 
the jumble of odds and ends ir an old tool-chest, we are able to 
grasp and enumerate only a very few, perhaps four or five, of these 
objects. 

For the scientific study of the area or range of visual attention, 
psychologists employ some form of short exposure apparatus, or 
tachistoscope^ (Greek, tackistos, very rapid, and skopein, to view). 
The essential idea of a tachistoscope is to furnish a field upon which 
S may fixate his glance and attention, and to supplant this field for 
a brief instant by another which contains the tesc-material. There 
is, then, a pre-exposiire field (which contains a fixation-mark), an 
exposure-field, and a post-exposure field. The contents of the 
exposure-field depend, of course, upon the object of the experi- 
ment. In the main, the tachistoscope has been most used for the 
experimental investigation of the process of reading, and, accord- 
ingly, with an exposure field containing printed texts, isolated 
words, nonsense syllables, single letters, etc., but it has also been 
used for determining the range of attention for the visual appre- 
hension of groups of lines, geometrical drawings, objects, colors, etc. 

' The recent work of Geissler (The measurement of attention, in A. J. P.> 
20: 1909, 473-529) has shown that the theoretical conclusion of p. 221 is 
justified in actual experimentation, though his methods are too elaborate 
to serve the purpose of simple functional tests. 

- The name Tachisloskop was first employed by Volkmann (27) 



TEST 24: RANGE OF VISUAL ATTENTION 223 

As Dodge has remarked, "no psychological instrument is subject to greater 
modification in response to special experimental conditions than exposure 
apparatus," and it may be added that in no other experiment are the 
results more evidently conditioned by the form of apparatus and type 
of procedure employed. For these reasons, it is advisable to review 
briefly the development of the instrument in the light of the experimental 
requirements. 

Wundt has formulated the essentials of a good tachistoscope as follows 
(29): 

(1) The exposure must be short enough to preclude eye-movements. 

(2) The arrangement of the fixation-mark and of the stimulus must be such 
that all the constituents of the exposed object can be seen with at least 
approximately equal distinctness, i.e., the exposure-field must coincide 
with the ocular field of direct vision. 

(3) The exposure of all parts of the field should be simultaneous, or so 
nearly so that there shall be no noticeable time-differences in the illumina- 
tion of the various regions. 

(4) Retinal adaptation must be favorable, and sudden transitions from 
dark to light must be avoided. 

(5) Persistent after-images must be avoided. 

(6) The duration of the retinal excitation must be limited enough to pre- 
clude roving of attention over the exposure-field. 

(7) A ready-signal must be given at an appropriate time before the ex- 
posure. 

Further requirements given by Dodge^ are as follows: 

(8) The relative illumination of the pre-exposure, exposure, and post- 
exposure fields should be capable of experimental modification. 

(9) The exposure should be noiseless and free from distraction. 

(10) It should be possible to arrange for monocular or binocular observa- 
tion. 

The earliest exposure apparatus, as used by Dove, Zdllner, and Helm- 
holtz, and described by Helmholtz (14, p. 710), made use of the electric 
spark for illumination. Here, although the duration of the spark is but 
0.00004 sec, the retinal excitation of the darkness-adapted eye is longer 
than is obtained from an exposure of the same object for 0.01 sec. in day- 
light. 

The use of a rotating disc for tachistoscopic experimentation is illus- 
trated by early devices described by Helmholtz (p. 514), and more fully 
by Exner (10), and employed, though for somewhat different purposes, by 
Exner and by Baxt (1). An elaboration of the rotating disc apparatus was 
used by Goldscheider and Miiller (11), and the principle is embodied in a 
recent rotating mirror tachistoscope by Wirth (29). Here the fixation-field 



' See also Erdmann and Dodge (8, pp. 94 ff.) for special requirements for 
the investigation of reading. 



224 ATTENTION AND PERCEPTION 

is a virtual image obtained from the revolving mirror and the exposure-field 
is a real image viewed through an adjustable slit in the circular mirror, 
which is revolved by a constant speed motor. A very simple adaptation 
of the rotating disc apparatus is illustrated in the weight-driven sectors 
used by Quantz (24) and another by the apparatus prescribed by Titchener 
(26, ii., p. 201), while the instrument here employed for the range test may 
be regarded as a modification of this form. 

A well-known exposure apparatus is the fall or gravity tachistoscope 
employed by Cattell (4), Huey (17, 18) and others. In this instrument, 
exposure is accomplished by the drop of a guillotine-like screen, perforated 
with a horizontal slit of variable width, before a card bearing the exposure- 
field. To render the exposure more nearly simultaneous, to afford a wider 
range of exposure-times, and to secure more accurate fixation, this instru- 
ment is now made with taller columns, with an Atwood-machine attachment 
and with a new form of fixation-field, as illustrated by Zeitler (31, p. 381). 
Monocular vision with the aid of a reading telescope is also introduced. A 
large demonstration form of the fall-tachistoscope is figured by Wundt. 

A pendulum exposure apparatus is shown in Wundt (p. 400), also in Zim- 
merman's catalog (1897, p. 8). The pendulum has also formed a constituent 
part of other tachistoscopes, e.g., as a device for interrupting a flash of light, 
as in Sanford's dark-box for testing legibility of various forms of type (25), 
or in Dodge's tachistoscope. 

The horizontal exposure used by Volkmann is seen again in Hylan's simple 
rubber-band and shutter type of tachistoscope (19, pp. 395 and 509). 

Another simple device is the superposition of a photographic shutter 
4 cm. in diameter over the test-material (Binet, 3). 

The use of a transparent mirror gives the cue to the construction of 
Dodge's latest instrument (6, 7, also described in Judd, 206, p. 234), which 
embodies all the requirements above cited. This instrument is to be recom- 
mended for those who wish to do careful work under experimentally varied 
conditions. Its only disadvantage is the necessity of employing a high-power 
illuminant, such as the arc light or 150 C.P. stereopticon incandescent 
lamp. The instrument costs about $20 without lamp, discs, exposure 
pendulum and other accessories. 

The apparatus used by Erdmann and Dodge (10, 98 ff.) andbyBecher (2) is 
of the camera obscura type, in which ati image of the exposure material is 
cast by a beam of light upon a ground glass field, and the illuminating beam 
interrupted by suitable devices. 

The controversies concerning the interpretation of the results secured 
by these various instruments have to deal, so far as technique is concerned, 
with four main problems: — (a) How essential is absolute simultaneity of 
exposure? (6) How carefully are convergence and accommodation controlled 
by the fixation-point? (c) How long is, and how long should be, the actual 



TEST 24: RANGE OF VISUAL ATTENTION 225 

duration of the retinal excitation set up by the exposure? (d) What are the 
optimal conditions of general and local adaptation? A brief discussion of 
these issues is essential to the intelligent examination of the results of tachis- 
toscopy. 

(n) Simultaneity of exposure. Erdmann and Dodge contend that abso- 
lute simultaneity of exposure over the entire field is a prerequisite for suc- 
cessful tachistoscopy, and they therefore discount experiments, especially 
those of Cattell, that have been performed by falling screen and disc tachi- 
stoscopes. Wundt, however, maintains that Cattell's fall-tachistoscope 
gives us virtual simultaneity when we regard, not the physical exposure, 
but the retinal excitation which it induces. Hylan's demonstration that a 
series of letters may be exposed seriatim from right to left or from left to 
right indifferently, so far as the resulting experience is concerned, appears 
to confirm Wundt's position. 

(6) Fixation. In the Cattell instrument, the fixation-point lies 3 mm. 
in front of the test-card. Sanford pointed out that this arrangement pro- 
duced faulty accommodation with a tendency to double-images. Erd- 
mann and Dodge show that at the ordinary reading-distance,' the displace- 
ment amounts to 0.6 mm., and this fact affords, in their opinion, the explana- 
tion of the relatively small number of words that could be read by Cattell's 
(S's in comparison with their own. As already noted, this difficulty is 
remedied in the improved fall-tachistoscope. In the simpler moving- 
screen instruments in which the fixation-point is placed on the screen, 
there is undoubtedly a tendency toward ocular reaction, i.e., toward fol- 
lowing the movement of the fixation-point, with consequent disturbance 
of fixation for the ensuing exposure. 

It should be made clear that the center of attention does not necessarily 
coincide with the fixation-point. Furthermore, there is, strictly speaking, 
no such thing as a fixation-point, and no "punctiform functional center of 
the retina" (Dodge, 7) on which impressions are centered when attended to. 
The eye-muscles of a perfectly normal *S are subject to relatively slow 
fluctuations of tension (fixation pseudo-nystagmus), so that what is termed 
the fixation point is really a fixation area. There are also slight movements 
of the head, due to pulse, breathing, fluctuating muscular tonicity, etc., 
even when elaborate forms of head-rest are provided. 
', / (c) Duration of exposure. The times chosen for objective exposure have 
varied from 1 to 1000 cr (o- representing 0.001 sec). Thus, Cattell used from 
\<7 up, and placed the optimal time at lOtr. Messmer concluded that 2o- was 
sufficient after practise. Goldscheider and Miiller employed lOo-, Huey 
15<r, Zeitler 10-20o-, Binet about 70o-, Hylan 3. 6(7 in seriatim letter exposures 



' No careful study of the optimal reading-distance seems to have been 
made. From 30 to 10 cm. is ordinarily used, but]Hylan performed tests with 
a distance of 1 m. 



^l 



226 ATTENTION AND PERCEPTION 

and 42ff for other tests, Erdmann and Dodge lOOo-. The primary object 
in using the smallest of these exposures has been to eliminate the possi- 
bility of eye-movement, and in the case of some investigators, e.g., Zeitler, 
to eliminate the roving of attention, and to simplify, if possible, the 
psychical processes subsequent to exposure. 

In so far as eye-movement is concerned, it is scarcely necessary to reduce 
the exposure-time to the limits used by most investigators, since recent 
*'T' studies of eye-movements and of reading-pauses indicate that the average 
eye-movement reaction is above 150<r (Dodge, 7), while the average dura- 
tion of normal reading pauses is placed at 185cr (Huey), with a lower limit 
of lOOo-, or, in the case of forced rapid reading of completely familiar texts, 
\of not less than 70-100(7 (Dodge). 

1 In so far as roving of attention and other psychological complications 
are concerned, it seems probable, as will be shown later, that there is no 
adequate sanction for the use of these minimal exposures, and Dodge is 
doubtless correct in saying that an exposure of lOOcr "guarantees what is 
physiologically a single visual act." 

(d) Adaptation. This consideration of objective exposure-times is, how- 
ever, but introductory to the real problem. In brief, the objective dura- 
tion of exposure is not the subjective duration of exposure. At the moment 
of exposure there is a slight lag in excitation, due to retinal inertia, but this 
is a negligible matter of some 2a-. When, however, the objective exposure 
ceases, the retinal excitation persists for a relatively long time. As the 
duration of this persistence of excitation depelTds very largely upon the 
adaptation of the retina and the relative brightness of pre-exposure, expos- 
ure and post-exposure fields, it is evident that the published exposure-times 
are meaningless unless we know the conditions of general and local adapta- 
tion under which they were made. Thus, an exposure of 30o-, with all three 
fields of equal illumination, is estimated to be approximately equal to an 
exposure of la with a pre- and post-exposure field of black. In further 
illustration, Wundt's controversy with Erdmann and Dodge (Wundt, Erd- 
mann and Dodge, 9,Becher) hinges in part upon the question : — how long was 
the retinal excitation (Bildzeii) that was secured under the experimental 
conditions used by Erdmann and Dodge when their objective e.\posure was 
lOOcr? Wundt estimates 250<t, Erdmann and Dodge, 150o-, Becher, less than 
150cr. Into the merits of these estimates, it is not here the place to go. Iir 
general, it is well to work in diffuse day-light adaptation. As regards local 
adaptation (relative brightness of the three fields directly used in the test), 
we may conclude that it is well not to have the post-exposure field stimulat- 
ing, i.e., brighter than the exposure-field, and that a black pre- and post- 
exposure field affords the most brilliant exposures, with longest retinal 
effects. Under these conditions, which are supplied by the apparatus 
used in this test, an exposure of .50-75^ will give a well "cleared-up" image 
(to employ Dodge's term) and will eliminate eye-movement. 



TEST 24: _ RANGE OP VISUAL ATTENTION 



227 



Apparatus. — Disc tachistoscope (Fig. 49).^ Frosted tubular 
lamp, 16 C. P. Two 4-iiich clamps. Blanks of cardboard 9 cm. 
square. Two complete sets of Willson's gummed black letters and 




Fig. 49. disc tachistoscope. 

figures, Size 3. Drawing ink and ruling pen. Head-rest,- with 
suitable supports and clamps. [Fifty-vibrations dry-contact fork 
(Fig. 50.) Dry battery. Connecting wire.] 



1 This instrument, devised by the author and employed by him in study- 
ing the effect of practise on the range of attention does not fulfill all of the 
requirements of the ideal tachistoscope, but it has the merit of being rela- 
tively inexpensive, simple in operation and construction, and of answering 
satisfactorily for comparative tests. It has also been designed with a view 
for use both for these short and for much longer exposures (Test 25). . 

^ Suggestions for the construction of head-rests are given by Judd. 



228 



ATTENTION AND PERCEPTION 



1/ Preliminaries. — Prepare a series of exposure-cards by use of 
the gummed letters and figures. Paste the letters smoothly and 
evenly, and center the series on each card. The test-object should 
include isolated letters, groups of letters, or letters mixed with digits 
in norserse arrangement, ir numbers from two to eight or ten per 
card. Prepare other cards with short words, short sentences, or 
columns of digits. Prepare still others with the aid of drawing ink 
so as to present regular or irregular series of lines, geometrical fig_ 




Fig. 50. fifty-vibrations dry-contact fork. 

ures, surfaces, etc., in varied fashion.^ It is well to confine the 
objects, in so far as possible, to an area 50 mm', wide and 35 mm. 
high. Exposure cards can also be formed, after the method used 
by Huey, by pasting bits of printed texts of various dimensions 
on the blanks, or colored surfaces may be introduced ad libitum. 

Set up the tachistoscope, and clamp or screw it firmly to the 
table. Connect the electric light to a circuit of proper voltage. 
By means of the supports and clamps, adjust the head-rest so 
that aS's eyes shall be about 40 cm. in front of, and slightly higher 
than, the exposure card. 

Adjust the tachistoscope for a point-exposure of 60(t.- 



' For suggestions, see Huey, 18, pp. 75 ff., and Binet, 3, p. 349. 

2 The time of total exposure of several rows of objects is not the same as 
that of the exposure of any single point. If t is the time required for the 
notched portion of the disc to pass a given point on the exposure field, and 
L is the time of exposure of the group of objects to be determined, and if 
H and h are the heights of the total exposure field and of the portion of the 

field occupied by the objects, respectively, then L = I (!+//)• 



TEST 24: RANGE OF VISUAL ATTENTION 229 

The pendulum-arm is attached with its mm. scale in view at the back of 
the instrument, and with the zero end of its scale lying upon the release- 
lever when the instrument is ready for exposure. To secure an expos- 
ure of 60o-, £■ should sot the first weight at 5 cm. (measured at the edge of 
the weight nearer the lever), should set the second weight at 60 cm. 
and should open the sector 25 deg. He may fasten the overlapping edges 
of sector and disc by pushing a small paper-clip over them at the periphery. 
The entire disc is to be tightened up upon its axis in such a position as to 
bring the square opening in the disc in alignment with the square opening 
in the screen. ^ 

See that the device that lifts the fixation-card works smoothly and quietly. 
The movement of this card should be invisible to S, and the stimulus-object 
should be entirely unobstructed by it at the moment of exposure 

Method. — Seat S so that his head is supported in the head- 
rest without undue strain (Fig. 51). Set the tachistoscope for 
an exposure, and place a very simple exposure-card in the holder. 
In this position of the disc, the exposure-card is hidden by the 
fixation-card, which is visible through an .opening in the disc. 
Instruct S to fixate the cross of the fixation-card as accurately 
and intently as possible, and, when he feels that his attention is 
thoroughly prepared, to signal for the release of- the disc.^ Let him 

^ If he wishes to measure the time of exposure accurately, E may attach 
a piece of smoked paper temporarily to the back face of the disc, connect 
the 50-vibs. fork with the battery, and adjust the fork so that its recording 
point (or the recorder of a sensitive signal-magnet, e.g.', a Deprez signal 
with which the fork is electrically connected)leaves its curve traced upon the 
paper when the disc is released. He may then determine the time of 
exposure by counting the number of 'waves' recorded while the notched 
portion of the disc is passing the center of the exposure field. 

Or he may apply the fork directly to a smoked kymograph drum (see Test 10) 
and record the duration of the exposure with a signal-magnet on a parallel 
tracing. For this purpose, the two clips fitted with light connecting wire, 
with which the instrument is provided, are placed on the periphery of the 
disc in such a manner that, at the moment of exposure and at the moment 
of occlusion of the center of the field, they make electrical contact with the 
copper brush which is fastened to the frame of the instrument. 

^ The rather unusual procedure of allowing S to control initiation of the 
experiment is justified here by the fact that the signal for the release may 
be very simple, and that we are more likely to secure maximal attention 
from (S. If, after several practise trials, it is evident that S is distracted 
by this procedure, E should revert to che usual method of giving the ready- 
signal himself. The practise series, in any event, need be no longer than 
is required to accustom <S to the general setting of the test. 



230 



ATTENTION AND PERCEPTION 



then report, orally or preferably by drawing, what he has seen. 
Unless attention is manifestly poor, do not repeat the exposure.^ 
Introduce more and more complex cards of the type under 
investigation until a limit is reached beyond which S cannot 
carry his observation. For the experiment proper, use in the 




'ESTING THE RANGE OF ATTENTION. 



main simple series of consonants, and drawings, but unless there 's 
some special reason for it, do not change without notice from the 
one type of exposure-card to the other. 

Variations of Method. — Test the range of attention with 
other forms of material, e.g., digits, nonsense syllables, words, and 

' There is, however, good precedent for using repeated exposures, if 
desired: Cattell used a series of 5 exposures; Huey occasionally, and Binet 
regularly, made as many as 20 exposures; Titchener prescribes an indefinite 
number of exposures. This procedure is based on the assumption that no 
more is actually seen in 20 exposures than in one, but that the series of 
exposures determines the limits of assimilative capacity. This method 
seems unnecessary, especially for comparative purposes. 



TEST 24: RANGE OF VISUAL ATTENTION 231 

especially with short sentences and drawings. Test the assim- 
ilative completion of word skeletons (groups of characteristic 
letters, mutilated or misspelled words, as illustrated under Results, 
13, c). Vary the time of exposure, especially toward the shorter 
times. Try changes in the backgrounds and fields by covering 
the screen and disc with white, gray and black papers in differ- 
ent combinations, and usirg gray or black blanks for exposure- 
cards. Try the cumulative method of exposure. Try reading 
distances greater than 40 cm. Try various sizes, forms, or col- 
ors of type. 

Treatment of Results. — S's rank is measured in general by 
the number of concrete objects correctly reproduced. This rank 
should be computed separately for different forms of exposure- 
card (if other thai) isolated letter tests are used) and for letter- 
series of different lengths, e.g., for 6-place, 7-place, 8-place series, 
etc. In the case of letters or words, the simplest method of rank- 
ing is to assign one unit for each letter or word correctly repro- 
duced, but to deduct 0.5 for errors of insertion or transposition. 
Thus, if the stimulus-card was FRMUTH, then FRMTUTH or 
FMRUTH would be ranked 5.5, whereas FRMUT or FRMUH 
would be ranked 5. If desired, double errors, e.g., transposition 
and insertion, as FMRTUTH, may be doubly discounted, but it 
is simpler to count this rendering also as 5.5. 

In the case of more complex exposure-cards, such as drawings, 
it is sometimes possible to rank S on the basis of the number of 
lines reproduced, discounting 0.5 for lines incorrectly placed with 
respect to the total figure; ii other cases, it is more satisfactory 
to assign a subjective estimate of the gereral fidelity of the repro- 
duction on some arbitrary scale, e.g., 10 for a perfect reproduc- 
tion, for absolutely nothing, and intermediate ranks in pro- 
portion. 

If the method of serial exposures is followed, ;S's rank can often 
be indicated by the number of exposures necessary to obtain 
accurate reproduction. 

Results and Conclusions. — (1) When a series of unrelated 
objects is exposed, the average number of impressions that can be 
grasped in a single exposure lies between four and five. While, 
occasionally, *S's may grasp as many as seven impressions, this is 



232 ATTENTION AND PERCEPTION 

usually due to a more or less well-recognized tendency to group 
or unify the objects in some manner. Table 30 summarizes the 
author's experiments (28) upon four college students with letter-series, 
100 0- exposure, and with the use of apparatus like that prescribed, 
save that the pre- and post-exposure fields were white. It Avill 

TABLE 30 
Average iVKmber of Letters Read Correctly in one Exposure (Whipple) 



OBSERVERS 


FIVE-PLACE 
SERIES 


SIX-PLACE 
SERIES 


SEVEN-PLACE 
SERIES 


ALL 


Mr. B 

Mr. E 


4.85 
4 84 


5.09 
4.49 
4.92 
4.86 


5.25 

4.48 
5.38 
4.40 


5.06 
4 53 


Mr. N 

Mr. T 


4.74 
4.51 


4.97 
4.71 


Average 


4 74 


4 84 


4.SS 


4.82 



be seen that . the average performance for different S'a under dif- 
ferent conditions is quite similar, and that it lies between four and 
five impressions. The 6- and 7-place series are somewhat more 
favorable because the *S's can occasionally reproduce 6 or 7 impres- 
sions. 
/ These results are in close accord with those of other experi- 
menters.* Cattell's tests (4) place the average limit for digits 
at 5, for letters at 3-4, and more often 3, though one S could grasp 
6 letters. Erdmann and Dodge found that 6-7 letters could be 
read at times. Zeitler (30) points out that, while a series of con- 
sonants has an assimilative limit of 4-7, one may grasp 5-8 impres- 
sions, if vowels are interspersed. In the author's experiments, it was 
found, similarly, that the 7-place series that were read successfully 
were almost always those containing vowels which permitted the for- 
mation of nonsense syllables, e.g., WAEGZME, KMDEMBH. 

' The horizontal seriatim exposure used by Hyhiii is so little comparable 
with the whole-field exposure of others that his results may not be expected 
to conform with theirs. Hylan found that, with an exposure of 6 letters 
at the rate of 3.6 <r per letter, an average of 1 .9 letters was read, while a longer 
exposure, 42o- for the entire card, permitted 2.6 letters to be read. 



TEST 24: RANGE OF VISUAL ATTENTION 233 

The statement that the first and last letters are those usually 
seen clearly is not so easily confirmed and does not apply to the 
results of all *S's. 

(2) S's not infrequently report that more is seen than can be 
remembered a moment later when the report is given. In such 
cases, it is still often possible to state whether or not a given 
character was present. 

(3) Despite the meaningless character of isolated letters, a 
series once exposed may be sufficiently well remembered to be 
recognized if used in the experiment again, even after a lapse of 
several days. 

(4) When familiar syllables are combined to form nonsense 
words, e.g., lencurhilber, 6-10 letters can be grasped in one exposure 
(Zeitler). 

(5) In the reading of isolated words, i.e., collocations of words 
that do not make sense, the results of different investigators 
show a lack of accordance. As in the case of letters, Cattell's 
results indicate a lower range than those of other investigators. 
Cattell placed the limit of grasp at 2-3 short one-syllabled words. 
Erdmann and Dodge (8) found that, in a single exposure, 4 iso- 
lated words can almost always be reaa, and very often 5. Again, 
single words of 19-22 letters can be read in one exposure without 
roving of attention. Some of Zeitler's S's could even read a 25- 
letter word, such as Aufmerksamkeitsschivankung. Becher read 
26^etter words with a single, electric spark exposure. In gen- 
eral, the difficulty of grasping words does not increase in propor- 
tion to their length, while Cattell's reaction experiments showed 
that short words can be named more quickly than letters. 

(6) When short words are combined into simple sentences, it 
is found that the average reading capacity is 4-6 words. Zeit- 
ler's *S's read such sentences when the total number of letters was 
20-30; Erdmann and Dodge report 4-6 words of 2-10 letters each; 
Cattell found the average amount 4 words, occasionally 6, though 
S could read at times a 7-word sentence. One of the longest 
correctly read sentences contained 34 letters: " Eine Tochter muss 
ihrem Voter gehorchen." 

Huey (17, 18) exposed for 15 a lines cut from magazines. His 
results show clearly the striking individual differences in the read- 



234 ATTENTION AND PERCEPTION 

iiig range, which practically every investigator has noted ;^ thus, 
one S read on the average continuously and correctly 10.25 mm. 
of the line, another 21.33 mm., a third 23.80 mm. and a fourth 
32.40 mm.2 Under very favorable conditions (attention, sub- 
ject-matter, etc.), one of Huey's S's could read a stretch of Hne 
50 mm. long (about half a line), e.g., such phrases as "condition 
of consciousness," or "the whole body converges," but these are 
not ordinary performances. 

In exposures of this sort the amount read to the left and to the right of 
the fixation-point is not at all equal, but varies in either direction accord- 
ing to the subject-matter, e.g., in the second phrase above, the fixation- 
I)oint was at the o of whole. The tendency is, as might be anticipated, to 
read more to the right than to the left. "In almost every case in which 
a large amount is read, far more is read to the right of the fixation-point 
than to the left." 

In these, as in other exposures, the extent of reading is curtailed in pro- 
portion as the word-groups resemble isolated words, as when divided by 
punctuation-marks. 

There is evidence to show that the unit of reading is the word, in as much 
as <S's see, or at least report, words or {)hrases rather than letters, even at 
the ends of the sections read. 

(7) If the exposures-card is composed of a series of 4-15 ruled 
perpendicular lines, 2 mm. apart, Cattell found that *S's could 
give the correct number of hres exposed, up to 4-6 only. Similarly, 
Goldscheider and Miiller (11) tried various combinations of straight 
and curved Hnes (10 a exposure), with the result that, if the arrange- 
ment was quite irregular, only 4-5 constituents could be grasped, 
but in proportion as the arrangement became more symmetrical 
(thus facilitating grouping or unitizing), the number of constitu- 
ents that could be grasped was increased. A symmetrical ai'range- 
ment of simple perpendicular strokes increased the observation- 
limit to 7, while a combination of straight lines into squares, sym- 
metrically arranged, permitted the apprehension <)f 5 squares, and 
hence of 20 constituent lines. Similarly, experiments with semi- 
circles, ellipses, etc., confirmed the general principle that the num- 

' Cattell concludes that there is a decided difference in the sensitiveness 
of the retinas in different *S's, but it is quite as likely that these individual 
differences are as much central as peripheral. 

- In the type used, 40 mm. was equal approximately to 26 letter-spaces 



TEST 24: RANGE OF VISUAL ATTENTION 235 

ber of constituent elements grasped in a short exposure is a func- 
tion of the degree of combination which these elements permit.^ 

(8) The apprehension of simple geometrical forms, e.g., circles, 
diamonds, oblongs, etc., cut from black paper and pasted on a 
white background, is easier than that of letters. Hylan's results, 
compared with his results for letters above, may serve for illus- 
tration. Six *S's averaged 7 forms, his poorest *S averaged 4.5, and 
his best S, 9.5 forms.^ Quantz's test of requiring <S's to name 
aloud, in order and as rapidly as possible, a series o" geometrical 
forms, colors or words, during an exposure of 0.5 sec. or 1.0 sec. 
is not strictly comparable to the short exposure tests: he found 
that forms could be named less rapidly than colors or words, and 
that, so far as forms are concerned, as many can be named with 
0.5 sec. as with 1.0 sec. exposure (2.75 and 2.8, respectively).^ 

If complex drawings which are not clearly related to well-known 
geometrical figures are used, the test becomes more difficult 
because the visual image cannot be identified or held by the 
assistai ce of verbal associates (Binet, 3). 

(9) Practise has a curiously small effect upon the range of 
attention, when once the period of preliminary habituation to the 
arrangement of apparatus and method is passed (Cattell, 4: Hylan, 
19, p. 396). The chief feature of whatever practise can be de- 
tected is an increase in ability to group isolated impressions into 
combinations. "Practise tends to unioe into a closer perceptive 
unity impressions first combined with difficulty" (Hylan). The 
practise effect for isolated letter series for a period of seven co ten 
days as found in the author's tests (28) is indicaced in Table 31.* It 

' An obvious illustration of this principle is seen in the reading of letters 
and digits themselves. For an account of Goldscheider and Mtiller's tests 
of the constituents of digits, etc., consult Huey (18, pp. 78 f.). 

^ Some idea of the quaUtative factors which influence the perception of 
liminal visual forms may be obtained from the experiments of Miss Hemp- 
stead, though these were conducted with different apparatus and by a dif- 
ferent method. 

^ Huey's statement (18, p. 54) that, according to Quantz, more could be 
read in a short than in a long exposure, is not substantiated by Quantz's 
tables, which merely show that relatively more can be read in a half-second 
than in a second exposure. 

■* The four ^S's did not take the same series, nor work for the same length 
of time, so that the data are too few to permit accurate averaging into three 
periods, save for N., and for E. in the 7-place series. 



230 



ATTENTION AND PERCEPTION 



is evident that if we discount the improvement due to adaptation, 
there is but a small enlargemei.t of the range through practise 



TABLE 31 

J'JJfcct of Practise upon the Perception of Letters {Whipple) 



First period |4.874.44|4 

Later period — T • ^^1 — 

Last period 4.784.774 




734.254.903.83 



084.905.40i5.80 



(10) The relation of tlu^ visual range of attention to age has 
been studied carefully only by Griffing (12), but by a method so 
peculiar^ as to make the applicability of his results m ordinary 
conditions rather dubious. Table 32 preserts Griffing's results 
in terms of the total number of letters correctly read ir. a series 
of 10 expos n-es of 6 letters each. Griffing concludes from these 
data that the r umber of visual impressions perceived "is a func- 

TABLE 32 

Relation of Visual Range of Attention to Age (Griffing) 



NUMBER OF S'S 


AGE 


LETTERS READ 


39 


7-9 


4 


77 


10-12 


13 


73 


13-15 


18 


132 


16-18 + 


27 



tion of individual growth, reaching its maxinunn only when the 
ol)server is fully developed." 

' Griffing's method was to expose with a fiill-ta(diistoscope for 0.1 sec- 
or 1.0 sec, to a group of 10 to 20 S's, six printed capital hitters, 48 mm. 
high, hut to vary the interval between the ready-signal and the exposure 
from 6 sec. to 1.5 min., or even 4 min., without the knowledge of the »S's, 
with the idea of testing "the observer's powers of prolonged attention" 
by keeping theni waiting an indefinite time for the exposure. In view of 
the well-known irregularity and fluctuation of attention under such condi- 
tions, it seems clear that the degree of attention present at the moment of 
exposure, at least in a short series of tests, is almost a matter of chance. 



TEST 24: RANGE OF VISUAL ATTENTION 237 

(11) Griffing found no difference befcAveer the sexes. 

(12) There is oi ly questionable evidence of a relation between 
the range of visual attention and mental ability. Griffing divided 
his pupils into three groups on the basis of teachers' estimates, 
and found that his 'A' group had a somewhat higher average 
range of attention than the other groups, but that there were 
marked exceptions, so that "many pupils must have good powers 
of attention even when they show no evidence of them to their 
teachers." It is possible, however, that the outcome of Griffing's 
test is more dependent on the interest and good-will of the pupils 
than on their intelligence, for, as Griffing himself says: "Children 
of the most active minds would be most interested in novel expe- 
riences." Cattell states that in his tests "obtuse porters" re- 
quired three times as long as educated persons to read a letter or 
word. Binet could not differentiate his bright from his dull chil- 
dren by the exposure of single words, but could differentiate them 
very clearly by the exposure of a drawing 20 times in succession.^ 

(13) The Qualitative analysis of the perceptive processes con- 
cerned in reading during short exposures has developed differ- 
ences of opinion with regard to the following points: (a) Is it pos- 
sible for roving of attention to occur in exposures which are suffi- 
ciently short to eliminate eye-movement? (b) Do we appre- 
hend words by wholes or by parts? (c) Are there certain letters 
or combinations of letters which give the cue for the perception 
of words, and if so, what are these letters? What share does the 
total length and general visual contour of a printed word have in 
its perception? (d) Do different readers adopt different methods 
of reading? Current opinions upon these obviously interrelated 
problems may be summarized as follows : 

(c) Roving versus distributed attention. The question here is : is attention 
so distributed during the retinal excitation that we apprehend simultan- 
eously all phases of what is read, or does attention 'rove' from one portion 



' Binet's »S's drew what they could of the drawing after each exposure 
of 70er. An interval of 5-10 sec. was interposed between the exposure and 
the drawing. Only three of 11 S's were able to give a correct copy within 
the limit set to the test; these three S's were all of the group selected for 
superior intelligence. For reproductions of the actual drawings, consult 
Binet, 3, pp. 351-360. The original drawing is the left-hand one shown 
in the Binet-Simon graded tests, in Chapter 13, Fig. 59. 



238 ATTENTION AND PERCEPTION 

to another of the visual stimulus? The discrepancy, noted between the 
results of Cattell and of Erdmann and Dodge (5, above) is attributed by 
Wundt to the use of too long an exposure with consequent roving of atten- 
tion (and also, in part, to familiarity with the words to be used). Erdmann 
and Dodge, however, deny that roving took place during the visual phase 
of the experience, and assert that whatever roving occurs is confined to the 
motor-acoustic interpretation of what is seen: they find an explanation for 
Cattell's results in imperfect accommodation. They also point out that 
(S's can often recognize a word under conditions such that its constituent 
letters cannot be recognized, so that a rough visual image of the whole 
word must suffice for its recognition by associative supplementing— a 
fact that shows how difficult it is to distinguish between what is actually 
seen and what is 'centrally' supplied in tachistoscopic expei-iments. The 
varied experiments of Becher confirm the position of Erdmann and Dodge. 

Hylan (19) and Pillsbury (23, ch.v.) contend that there is, strictly speaking, 
no simultaneous distribution of attention at all in tachistoscopy, only succes- 
sive acts of attention applied to the "mental after-image." If we see four 
or five objects it is because "the result of a single glance persists long 
enough for four or five acts of attention to take place.' ' This mental after- 
image is distinct from the ocular after-image, though a direct product of 
stimulation and conditioned by physiological processes. Hylan estimates 
its average duration at 2.8 sec, and believes that individual phj^siological 
differences in this duration determine the number of objects that can be 
apprehended in one so-called pulse of attention. 

(b) Reading by wholes or by parts. Intimately connected with the ques- 
tion of the roving of attention is the question: do we read by wholes or by 
parts? It has been a time-honored idea, fortified by certain observations 
by psychiatrists (Grashey and Wernicke, especially) upon aphasic patients, 
that we read letter by letter. Cattell was convinced, however, that words, 
and even short sentences, if read correctly, or even if read with some false 
interpretation, are grasped as a whole, so that their component parts appear 
plainly and simultaneously in consciousness. Erdmann and Dodge simi- 
larly believe that we commonly perceive words as wholes. Goldscheider 
and Miiller conclude that words are recognized either as syntheses of their 
perceived component letters or as individual units, the latter being the 
more usual method. Messmer reaches similar conclusions. Zeitler dis- 
tinguishes between apperception (an immediate process conditioned largely 
by the objective image) and assimilation (a mediate process taking more 
time), and has sought to eliminate assimilation by using a very short expos- 
ure. He concludes that, on account of long practise and familiarity with 
words, we seem to read them as wholes, but that, in reality, there is a 
quick succession of processes, by a passage of attention, not from letter 
to letter, but from one to another of a series of prominent letters and letter- 
combinations. He believes that Cattell failed to note this succession 
because his exposures were too short, and that Erdmann and Dodge were 



TEST 24: RANGE OF VISUAL ATTENTION 239 

misled by the illusion of simultaneous assimilation. Dodge (7), however, 
asserts, as already indicated, that this alleged successive apprehension is 
really a successive review of the memory-image of an inadequately 'cleared- 
up' exposure. If the exposure is adequate for full clearing-up, we find 
simultaneous visual apprehension. Becher (2) has shown that geo- 
metrical-optical illusions, which Wundt instances as typical assimilations, 
can be fully apprehended in a lOo- exposure: he argues from this that Zeitler 
could not exclude assimilation by his short exposures. 

(c) Dominating and characteristic letters. Investigators like Goldscheider 
and Midler, Zeitler, and Messmer, who argue against reading by wholes, 
do not assert that we read letter by letter, but rather that certain promi- 
nent letters which 'stand out' in the visual image give us the cue for the 
acoustic-motor supplementing which forms such a prominent part of the 
process of reading; the interpretation is also, of course, greatly assisted 
by knowledge of the context and of the immediately preceding words and 
phrases. These prominent letters are termed "dominating" letters by 
Zeitler, "determining" letters by Goldscheider and Miiller (11); the 
other letters are termed "indifferent." As dominating letters, Zeitler 
mentions those which project above and below the line, and x and z. Mess- 
mer maintains that letters that project below the line are not so important; 
"they possess optically the value of small letters," and are often mistaken 
for these: again, they are relatively infrequent; e.g., in a sample passage, 
Messmer found 238 letters projecting above the line to 32 projecting below. 

There are also, according to Zeitler, dominating syllable-complexes, and 
in very familiar sentences, dominating words. The perception of these 
dominating elements suffices for the perception of the entire word or sentence, 
while indifferent letters or syllables may be altered or eliminated without 
affecting the reading. In reading, therefore, attention moves along a series 
of these dominating elements. At the first instant of exposure, the ele- 
ments have acertain "elbow-room," and (if we may mix metaphors) "hover" 
about till they get "anchored" by assignment into some total word-com- 
plex in accordance with the sense of the passage. "The word-form remains 
indeterminate and is first established through the sense of the passage." 
Direct visual completion of the words takes place. Goldscheider and 
Miiller, however, are convinced that the filling-out takes place only after 
the arousal of auditory imagery set off by the determining letters. In any 
event, the indifferent letters are so readily supplied that, when the deter- 
mining letters only of a word are exposed, many S's report that they have 
seen the entire word clearly, e.g., C ntr m for the German Centrum. This 
visual clothing of word-skeletons is a striking example of Miinsterberg's 
statement that "reproduced sensations under favorable conditions cannot 
be distinguished from sense-impressions." Similarly, a considerable amount 
of substitution will pass unnoticed, if restricted to indifferent letters; 
Zeitler's /S's, for instance, read hallucination when hnUnciuotion was 
exposed. The common experiences of proof-reading supply further illus- 
trations. 



240 ATTENTION AND PERCEPTION 

In their analj'sis of dotormining letters, Goldscheider and Miiller 
found that the first and the last letters in each word, especially the first, 
are almost always determining. Similarly, by another form of experiment, 
Huey discovered that the first half of a word is commonly more important 
than the second half. These investigators, however, did not find that 
consonants were necessarily more important than vowels. 

Messmer places less insistence upon dominating letters, at least for some 
readers, and directs attention rathdr to the total optical impression, or 
word-form, as a well-nigh exclusively significant factor in visual perception. 
In the relatively long pauses of normal reading, the dominating letters play 
a smaller role than in short-exposure experiments, since there is more oppor- 
tunity for all the letters in the word to affect consciousness. For the same 
reason, the total word-form becomes more important. Messmer, for instance, 
contrasts the dull evenness of such a word as zusammenreisen with the optical 
'rhythm' of such a word as Verschiedenheiten. So one might contrast the 
words consciousness or amusement with the words orchestration or pedagog- 
ically. Hamilton (13) concludes that in most cases the general character- 
istics of a word afford the cue for its recognition. 

Becher, like Erdmann and Dodge, insists on the primary importance 
of the total optical contour, or word-form. In this contour, the so-called 
dominating letters of Zeitler play a determining role because they are 
characteristic and prominent letters, but they are not apprehended suc- 
cessively. 

(d) Individual differences in manner of reading. Goldscheider and Miiller 
believe that the relative importance of consonants and vowels as determining 
letters depends in part on the reader's ideational type. They also believe 
that the method of reading may shift from sentence to sentence, from word 
to word, or even within the same word, according to the general ease and 
familiarity of the reading-matter; in general, with unfamiliar words, the 
tendency is toward perception by letters; contrariwise, the'more familiar 
the passage, the fewer visual cues are needed, and the stronger is the ten- 
dency to read by word-wholes. 

Readers, in Messmer's opinion, may belong to a subjective or to an objec- 
tive type: readers of the former type depend largely upon associative pro- 
cesses, and apperceive words in the main from the total character of their 
visual form; readers of the latter type make more use of the dominating ele- 
ments, read less at a glance, and are less likely to err. 

In conjunction with our earlier statement that "in no other 
experiment are the results more evidently conditioned by the form 
of apparatus and type of procedure employed," these final sug- 
gestions concerning fundamental individual differences in read- 
ing give us the basis for a tentative sunnnary of the anal.ytical 
results just set forth. The seeming lack of agreement between 



TEST 24: RANGE OF VISUAL ATTENTION 241 

the results of different investigators is, in short, due in part to 
the divergence in experimental conditions, in part of the diver- 
gence in type of the S's employed. We do not always read by 
wholes: neither do we always read by successive apprehension. 
The unit of attention, of visual apprehension, in reading is a vari- 
able quantity. In normal reading, assuming equally easy sub- 
ject-matter, the manner of reading will depend upon the type of 
the reader. Aside from differences in speed and fluency of read- 
ing, we may probably distinguish two fundamental types of read- 
ers, the subjective and the objective. The latter exhibit the fol- 
lowing characteristics: in tachistoscopic tests, their attention is 
directed to the optical fixation-mark; their range is small, e.g., 
three isolated letters or one 12-letter word, but they read accu- 
rately, are quite certain of what they do see, and seldom guess; 
for them there exists a distinct time-interval between the visual 
[)erception and assimilative interpretation or rise of meaning, and 
they seldom confuse these two phases. The subjective readers 
differ from the objective in every one of these points: they can 
read words lying in indirect vision; they have a range of five iso- 
lated letters or one 27-letter word; their attention is placed mainly 
on the interpretative or assimilative phase, and their reading 
occurs mainly by large word-wholes, or even by phrases, on the 
basis of relatively meager visual cues. Tliese subjective readers 
are not, however, necessarily the faster.^ 

If, now, the subject-matter is difficult, the tendency for the 
subjective type of reader is toward the more extensive use of vis- 
ual symbols, and here, doubtless, as in the case of short exposures, 
dominating letters or complexes become more important: it will 
depend upon the difficulty of the passage whether these letters 
play their chief role as prominent elements in the configuration 
of the word, or whether they are directly the, object of attention. 

If the subject-matter is very difficult, e.g., the reading of begin- 
ners, or of an adult in a foreign language, especially if reading 
unfamiliar characters, such as Greek or Hebrew, we have an 
extreme case in which reading may, and often does, proceed let- 
ter by letter. 

' For a more detailed discussion of these tjpes, sec Meuiuann, ii.,250ff. 



242 ATTENTION AND PERCEPTION 

The readirg of children, once the primary mechanical difficul- 
ties are mastered, is almost always of the subjective or interpre- 
tative type (Messmer), though for different reasons than in the 
case of the subjective reading of adults. 

Whatever the type of reading or reader may be, we are never 
free from the presence of a mass of 'central' associates. The con- 
sequent processes of assimilation are a constant accompaniment 
of all normal reading. The attempt to eliminate assimilation by 
the use of extremely short exposures defeats its own end, and such 
exposures create artificial conditions, foreign to those of normal 
reading. 

Notes. — Dr. W. McDougall of London has devised a test that 
is worthy of mention here because of the results that it has yielded 
and because of its evident similarity to the tachistoscopic expo- 
sure of geometrical figures. This test, which he calls the 'spot- 
patterr' test, may be said to measure ability to apprehend topo- 
graphic relationship. A card 10 cm. square is pierced with eight 
or ten holes, each 1 mm. in diam. These perforations form an 
irregular pattern within an area 1.5 in. square, but always coin- 
cide with intersections of an imaginary system of vertical and 
horizontal lines | in. apart. One face of the card is now covered 
with clear, dead-white paper^ and the whole card is placed in an 
aperture of a screen in the path of a beam of light to *S's eye. By 
means of a photographic shutter, the light is flashed upon the card 
in groups of 5 flashes, each lasting 20 a, and at the rate of one every 
2 sec. After each series of 5 flashes, S is asked to make a map of 
the spots of light upon a bit of squared paper 1.5 in. in size, ruled 
to correspond to the system of lines above mentioned, i.e., m 
J in. squares. He is told the number of the spots, and that each 
spot must fall at the intersection of two lines. He attempts a 
new map after each 5 flashes, until he makes an accurate repro- 
duction. It is of special interest to note thar this test has given 



' This arrangement makes it possible to work in daylight and without the 
interposition of any screens or fixation cards before the exposure-card, since 
the perforations remain invisible until lighted up by the beam of light pass- 
ing through them. The test might, however, be adapted to the tachistoscope 
already described 'by using simple black dots in place of the perfora- 
tions, and perhaps substituting a single longer exposure for the series of 
short exposures, the exact significance of which is not clear to the author. 



TEST 24: RANGE OF VISUAL ATTENTION 243 

very high correlations with abihty as shown in general school per- 
formance.^ 

REFERENCES 

(1) N. Baxt, Uebcr d. Zeit welche nothig ist, daiuit eiu Gesichtsein- 
druck zum Bewusstsein kommt, etc., in Pfliiger's Archiv f. Physiol., 4: 
1871, 325-336. 

(2) E. Becher, Experimentelle u. kritische Beitragc zur Psychologie des 
Lesens bei kurzen Expositionzeiten, in Z. P. 36: 1904, 19-73. 

(3) A. Binet, Attention et adaptation, in A. P., 6: 1899 (1900), 248-404. 

(4) J. Cattell, The inertia of the eye and brain, in Brain, 8: 1886, 295- 
312; also as Ueber die Tragheit der Netzhaut u. des Sehcentrums, in Ph.S, 
3: 1886, 94-127. 

(5) R. Dodge, An improved exposure apparatus, in P. B., 4: January, 
1907, 10-13. 

(6) R. Dodge, The psychology of reading, in P. R., 8: 1901, 56-60. 

(7) R. Dodge, An experimental study of visual fixation, in P. R. M.S., 
8: No. 4, 1907, (No. 35). Pp. 95. 

(8) B. Erdmann and R. Dodge, Psyehologische Untersuchungen liber 
das Lesen, Halle, 1898. Pp. 360. 

(9) B. Erdmann and R. Dodge, Zur Erlauterung unserer tachistoskopis- 
chen Versuche, in Z. P., 22: 1900, 241-267. 

(10) S. Exner, Ueber die zu einer Gesichtswahrnehmung nothige Zeit, 
in Sitz. Ber. d. Wiener Akad., 58: (2), 1868, 601-632. 

(11) A. Goldscheider and R. MiiUer, Zur Phys. u. Path, des Lesens, in 
Zeits. f. klin. Med., 23: 1893, 131-167. For critical summary, see Wallaschek 
in Z. P., 7: 1894, 228-231. 

(12) H. Grifiing, On the development of visual perception and attention, 
in A. J. P., 7: 1896, 227-236. 

(13) F. Hamilton, The perceptual processes in reading, in .Vrch. of Psych., 
No. 9, December, 1907 (Columbia Univ. Contr., etc. 17: No. 1). 

(14) H. Helmholtz, Handbuch d. physiol. Optik, Hamburg and Leipzig, 
1896. 

(15) Louise Hempstead, The perception of visual form, in A. J. P., 12: 
1901, 185-192. 

(16) E. B. Huey, Preliminary experiments in the physiology and psy- 
chology of reading, in A. J. P., 9: 1898, 575-586. 

(17) E. B. Huey, The psychology and physiology of reading, in A. J. P., 
11: 1900, 283-302 and 12: 1901, 292-312. 

(18) E. B. Huey, The psychology and pedagogy of reading, N. Y., 1908. 
Pp. 445. 



1 C. Burt, Experimental tests of general intelligence, in B. J. P., 3: Decem- 
ber, 1909, 94-177, especially 150 ff. 



244 ATTENTION AND PERCEPTION 

(19) J. P. Hylan, The distribution of attention, in P. R., 10: 1903, 373- 
403 and 498-533. 

(20) C. Judd, (a) Laboratory manual of psychology, N. Y.,1907. Pp. 
124. (b) Laboratory equipment for psychological experiments, N. Y., 1907. 
Pp. 267. 

(21) O. Messmer, Zur Psychologic des Lesens bei Kindern u. Erwachsenen, 
in Z. g. P., 2: 1903, 190-298. 

(22) E. Meumann, Vorlesungen zur Einfuhrung in die exp. Padagogik 
u. ihre psychol. Grundlagen, 2 vols., Leipzig, 1907. Pp. 555 and 446. 

(23) W. B. Pillsbury, Attention, London and N. Y., 1908. Pp. 330. 

(24) J. Quantz, Problems in the psychology of reading, in P. R. M. S., 
2: No. 1, 1897. 

(25) E. C. Sanford, The relative legibility of the small letters, in A. J. P., 
1: 1888, 402-435. 

(26) E. B. Titchener, Experimental psychology, vol. 1, Qualitative experi- 
ments, N. Y., 1901. 

(27) A. Volkmann, Das Tachistoskop, etc., in Sitz. d. k. s. Ges. d. Wiss 
Leipzig (math.-phys. CI.), 1859, 90 ff. 

(28) G. M. Whipple, The effect of practise vipon the range of visual 
attention and of visual apprehension, in J. E. P., 1: 1910, 249-262. 

(29) F. Wirth, Das Spiegeltachistoskop, in Ph.S., 28: 1903, 687-700. 

(30) W. Wundt, Zur Kritik tachistoskopischer Versuche, in Ph.S., 15: 
1899, 287-317, and 16: 1900, 61-70. See also his Volkerpsychologie, vol. 1, 
Die Sprache, 1900, 530 ff., and his Grundzlige d. physiol. Psychologic, 5th 
ed., 1903, 3: 611 f. (Note: the first half of vol. 1 of the 5th ed. is available in 
English, trans, by E. B. Titchener, N. Y., 1904. Vol. 1 of the 6th German 
ed. appeared February, 1908.) 

(31) J. Zeitler, Tachistoskopische Versuche liber das Lesen, in Ph. S., 
16: 1900, 380-463. 

TEST 25 

Visual apprehension. — This test is, in many respects, similar to 
that of the range of visual attention (Test 24), but it differs in 
certain important particulars: the period of exposure is increased 
from a small fraction of a second to several seconds, and the test- 
object is correspondingly more complex. Both eye-movement 
and roving of attention take place, so that we cannot speak of 
the range of attention ;i we are measuring, rather, the capacity 



' If one accepts the view of Pillsbury (4) and Hylan (3) that attention in 
tachistoscopy is really successive, this test differs from the former only in 
degree: we now give opportunity for a greater number of successive acts of 
'attention. 



TEST 25: SENSE OF VISUAL APPREHENSION 245 

to apprehend a number of disparate objects by visual examination 
during a short period. 

Tests of this type have been variously designated as tests of 
"quick perception," of ''observation/' of "degree of attention," 
or even as "memory tests." The term "apprehension," however, 
seems suited to describe the psychological processes under exami- 
nation. 

Very few investigators have employed this test under experi- 
mental conditions, but it has been long used as a source of amuse- 
ment in competitive parlor games, and it has been urged by some 
writers, particularly by Miss Aiken (1), as a source of mental 
training^ in the form of systematic schoolroom exercises. Quantz 
(5), in his investigation of the psychology of reading, used some 
exposures of 2 sec. : the author (7) has made a more extended study of 
visual apprehension, in order to see whether the remarkable practise- 
effects alleged by Miss Aiken could be confirmed under laboratory 
conditions. 

Two forms of the test are described: variations can be easily 
worked out to suit special conditions. 

A. THREE seconds' EXPOSURE WITH THE TACHISTOSCOPE 

Apparatus. — Disc tachistoscope^ and other material as in Test 
24, save that the cardboard blanks are replaced by blanks of stiff 

1 The famous conjurer, Robert Houdin (2) used what he termed "per- 
ception by appreciation" as a basis for certain feats of "second sight." 
The capacity which he and his son Emile attained is so marvellous as to be 
worthy of record. For preliminary tests Houdin tried the estimation of the 
numbers of dots on dominoes till, he says, " we at length were enabled to 
give instantaneously the product [sum?] of a dozen dominoes. This result 
obtained, we applied ourselves to a far more difficult task, over which we 
spent a month. My son and I passed rapidly before a toy-shop, or any other 
displaying a variety of wares, and cast an attentive glance upon it. A few 
steps further on we drew paper and pencil from our pockets, and tried which 
could describe the greater number of objects seen in passing. I must own 
that my son reached a perfection far greater than mine, for he could often 
write down fortrj objects, while I could scarce reach thirty. Often feeling 
vexed at this defeat, I would return to the shop and verify his statement, 
but he rarely made a mistake." 

This capacity may be compared with the results obtained by adults after 
practise for a mouth in the author's experiments : here the average number of 
objects named was but six, the maximum ten. 

2 A simpler, but less efficient, substitute may be contrived after the style 
of the 'krypteon' described by Sanford (6, p. 403). 



246 ATTENTION AND PERCEPTION 

paper 10 X 15 cm., and that the exposure-card holder and the 
opening in the screen of the instrument are adjusted to correspond- 
ing dimensions. Collection of pictures of all kinds, cut from old 
magazines and trimmed to a size not over 10 X 15 cm. [Seconds' 
pendulum, Fig. 21, or metronome with electrical contracts (Fig. 
14) and double time-marker. Fig. 20, in place of the 50-vibs. fork.] 

Preliminaries. — Set up the tachistoscope as described in Test 
24. Remove the fixation-card, or turn it off to one side. Replace 
the small by the large card-holder, and arrange the screen so that 
the rectangular replaces the square opening. Adjust the disc so that 
the pre-exposure section just covers the exposure-card when the 
instrument is set.^ Adjust the weights and the sector of the disc 
to give a point-exposure of 3 sec. This will be secured approxi- 
mately by setting the first weight at 10 cm., the second at 85.2 
cm., and opening the sector 115 deg. For rough determination 
of the exposure, the stop-watch (Fig. 13) may be used. For accur- 
ate determination, use the seconds' pendulum or metronome and 
the signal-magnet (time-marker) mentioned in Test 10; make the 
determination as directed in Test 24. 

The following types of exposure cards will be found desirable; 
10-20 cards should be prepared of each type selected, (a) Groups 
of irregularly arranged dots or small circles or crosses, in number 
from 6 to 20.^ These should be grouped in a space not exceeding 
35 mm. square in the center of the blank, and care must be taken 
to avoid too obvious hints of combinations in the groupings. These 
cards may readily be made by the use of the asterisk (*) sign of a 
typewriter. (6) Cards on which pictures — drawings, cuts, litho- 
graphs, etc., cut from magazines — have been pasted, (c) Cards 
containing a single line of 8-10 three-letter nonsense syllables. 
These may be prepared most easily by the typewriter. As it is 
important to avoid syllables that resemble words when pronounced, 
a selected list is given here. The last line may be used to illus- 
trate the effect of using sense syllables, (d) Cards containing 
varied combinations of lines in meaningless drawings. Make 
these with pen and ink; keep the drawings within an area 75 mm. 



' Fixation is not so exact, of course, with this arrangement, but in view 
of the long exposures, the error may be neglected for comparative work. 

^ Cf. Aiken (1, p. 37) who terms this the test of "unconscious counting."' 
Groups of about 14 dots prove satisfactory for testing adults. 



TEST 25: VISUAL APPREHENSION 247 

high and 130 mm. long; use combinations of arrows, circles, loops, 
and straight lines, with 10-15 of these elements in each drawing. 
One or two drawings with some hint of meaning, such as a con- 
ventionalized desk-telephone, a 'woodeny' disjointed horse, etc., 
may be introduced if E desires to secure light upon S'b use of 
verbal and other associations for holding the drawings in mind. 



vel 


ild 


bli 


ool 


vid 


elt 


arl 


ime 


arg 


tob 


zen 


rud 


bri 


euk 


zet 


lit 


omb 


Llll 


ept 


pha 


vem 


tud 


rab 


sef 


dak 


smi 


irm 


zin 


ibe 


urs 


eit 


urf 


ift 


ank 


ung 


nen 


ruv 


acq 


ong 


pru 


nis 


dri 


aum 


jur 


geg 


gla 


euf 


jek 


pof 


kun 


zud 


geb 


yef 


rik 


tau 


lud 


gur 


ige 


rin 


zib 


dro 


pum 


rin 


nuc 


ahn 


rad 


ite 


buh 


orm 


gos 


wol 


gah 


orp 


tef 


uff 


lei 


pru 


spo 


eig 


orl 


zig 


arb 


pud 


lorn 


teg 


cha 


baw 


ipp 


lin 


ith 


luh 


zan 


gom 


fid 


ruj 


heb 


ret 


lime 


ech 


tas 


tan 


end 


low 


rat 


not 


eel 


red 


add 


ton 


arc 



(e) Cards containing typewritten four-line stanzas from some not 
too difficult or too well-known poem. The object in using poetry 
is to secure a certain degree of equivalence in length, rhythm, 
style, and topic from one exposure-card to the next. (/) Cards 
containing columns of digits, as illustrated in Aiken, p. 30. A 
sample column from her book is the following: 

230 
729 

11 

36 
40000 

16 

40 

Method. — Proceed in general as in Test 24 (save that there is 
no preliminary fixation-mark). Inform S what type of card is 
to be exposed, i.e., a drawing, a stanza, etc. 

aS's reports may be as follows: for dots, a statement of their 
number, supplemented, if desired, by a rough pencil sketch of their 
position and an account of their grouping; for nonsense syllables, 
poetry, or digits, an oral or written report; for drawings, a pencil 



248 ATTENTION AND PERCEPTION 

sketch; for pictwes,a, verbal description, supplemented, if S desires, 
by a pencil sketch. In the case of pictures, E may also quiz *S' 
with regard to the observation of various details which S has not 
reported, to see whether they have actually escaped his observa- 
tion or have merely been neglected in his report, e.g., by the use 
of such questions as: "Did you notice any details in the back- 
ground?" "Is there any printing in the picture?" "What color 
was the girl's dress?" After S' report is finished, E may often 
obtain further light upon S's work by confronting him with the 
stimulus-card and asking him what features or details he had 
failed to note, what he had forgotten, or what he had misap- 
prehended. 

Treatment of Results. — Some of the material lends itself 
well, some but poorly, to quantitative treatment, but the latter 
is often most useful for qualitative analysis of the mental processes 
concerned. The following system, though obviously arbitrary, 
has been found serviceable, (a) Counting dots: assign credit for 
the reporting of the correct number only; consider any mistake, 
even of one number, a failure. (6) Pictures: estimate >S's grade 
upon a scale of 10, i.e., assign the grade 10 to a report which seems 
to indicate complete recall of all the salient features of the picture ; 
assign the grade to complete failure, and score intermediate grades 
accordingly. This grading may be made fairly objective by 
counting up the number of features or 'points' which are adjudged 
essential to a satisfactory report, and comparing the number 
given by S with this standard number for the picture in question, 
(c) Nonsense syllables: assign one unit to each letter correctly 
reported (e.g., 4 syllables = 12) . but deduct 0.5 for each error of 
transposition or insertion, whether of letters within syllables, or 
of the syllables themselves, (d) Drawings: as in the case of pic- 
tures, rate the reproduction on a scale of 10, by reference to the 
number of lines or elements correctly reproduced, in comparison 
with a standard number for the drawing in question, (e) Poetry: 
assign one unit for each word correctly reproduced, but deduct 
0.5 for each error of transposition or insertion. (/) Digits: as 
with nonsense syllables, assign one unit for each digit correctly 
reported, but deduct 0.5 for each error of transposition or insertion, 
whether of digits within numbers or of the numbers themselves. 



TEST 25: SENSE OF VISUAL APPREHENSION 249 

R. SIX seconds' EXPOSURE WITHOUT THE TACHISTOSCOPE 

Material. — Small table. Piece of cloth, preferably gray, large 
enough to cover the table-top. Seconds' pendulum (Fig. 21). A 
piece of cardboard about 30 X 45 cm., and a full-sized sheet (22 X 
28 in.) of gray cardboard. Collection of miscellaneous small ob- 
jects, familiar enough to be named by all the S's, e. g., pencil, rule, 
spoon, tin box, leaf, cup, bunch of keys, toy animals, salt-shaker, 
postcard, etc. Ten different objects will be needed for each 
exposure. 

Method. — Place the large sheet of gray cardboard on the table- 
Arrange on this as a l)ackground a group of ten objects, but avoid 
combinations of o])viously related objects, such as pen and ink- 
stand. Make a rough sketch of the group, with a list of the objects, 
so that it can be restored when desired for later tests. Cover with 
the gray cloth (to conceal the objects while S is taking his position 
and receiving instructions) . Let S now stand in front of, and close 
to, the table, but in a position that will not interfere with its full 
illumination. Let him hold the smaller sheet of cardboard so as to 
cut off the view of the table-top. Start the seconds' pendulum, 
which must be placed somewhat to one side, where it can easily be 
seen by E, but will not distract S. Remove the cloth and take the 
cardboard which S has been holding. Give S a "ready" signal, 
and 2' sec. later, quickly remove the cardboard screen. At the 
expiration of 6 sec.^ again cut off *S's view with the screen. Let 
him immediately turn his back to the table, and give a verbal 
description of the objects. 

The chief stress should be placed on naming as many objects as possible: 
afterwards, S may be asked to describe the details of the objects or to make 
a rough sketch to indicate their relative positions. For qualitative purposes, 
S should be encouraged to give an account of the manner in which he ob- 
served the objects and the manner in which he has reproduced them. After 
S has enumerated as many objects as possible, exhibit the objects that were 
unnamed, either singly, or mingled with a number of objects not on the 
table, and ask S if he can identify any more of the objects exposed. 



1 The simplest method is to count the strokes mentally, "one, two, three," 
etc. : if the exposure is made at "one," the screen is to be restored, of course, 
at "seven." 



250 ATTENTION AND PERCEPTION 

Treatment of Results. — Credit S with one unit for each 
object named. 

Results for Both Methods. — The following results are based 
on the author's trial of these tests with three adults, G and R 
(young men, experts in psychology), and V (a young lady school 
teacher, with a small amount of psychological training). 

(1) The most striking quantitative result is the very small 
increase in the range -of apprehension in comparison with the range 
of attention (Test 24). Thus, in an exposure of 10-50o-, an average 
*S can grasp 4 or 5 objects: here, with an exposure more than 100 
times as long, the average S enumerates but 6 objects (with a mini- 
mum of 3, and a maximum of 10). Similarly, 3 sec. exposure of 
nonsense syllables allows, on the average, 10.15 letters (Table 33), 
i. e., between 3 and 4 syllables, to be read correctly, which is ap- 
proximately the same as can be read with exposures of a small 
fraction of a second. On the other hand, the 3 sec. exposure of 
sense material gives an average "range" of nearly 12 words in con- 
trast to the 4-6 word limit for ordinary tachistoscopy. This inter- 
esting advantage of sense material in the longer exposure is evi- 
dently' due to the fact that such material can be grouped and re- 
called by larger and more meaningful units, whereas the hetero- 
geneous combinations of nonsense syllables or disparate objects are 
more difficult to identify and recall. In the case of poetry, *S's feel 
that the limit of their performance is set simply by the amount 
that can be read during the exposure, whereas, even in the' 6 sec. 
exposures, there is not time enough clearly to apprehend 10 dis- 
parate objects. The maximal reproduction of poetry was that of 
R, who read the first 19 words of the following, with 3 sec. exposure: 

"Were they unhappy then? It cannot be. 
Too many tears for lovers have been shed, 
Too many sighs give we to them in fee, 
Too much of pity after they are dead." 

(2) Individual differences in capacity for quick apprehension are 
clearly indicated by Table 33. Thus, V excels in the estimation of 
dots and in reading poetry, but is the poorest S in reading nonsense 
syllables, in reproducing drawings, or in describing pictures and 
objects. G excels in these performances, but is handicapped in 



TEST 25: 



VISUAL APPREHENSION 



251 



TABLE 33 
Individual Differences in Visual Apprehension (Whipple) 



MATERIAL 


DOTS* 


PICTURES 


nonsense: 


DRAWINGS 


POETRY 


OBJECTS 


G 


11/33 
16/35 
28/35 


6.96 
6.89 
4.40 




10.90 
10.70 

8.85 


8.65 
6.42 
3.70 


9.42 
12.92 
13.21 


7 10 


R 


5 57 


V 


5.50 


Average . . . 


1 6.09 


10.15 


6.26 


11.83 


6 03 



* Efficiency is Indicated here by the number of times the group of dots was correctly reported, 
i.e., II out of 33 trials, etc. As G. missed two trials, the average cannot be figured exactly. 

reading poetry by his relative unfamiliarity with Enghsh poetry 
(he is of German descent): his poor capacity in estimating dots 
cannot be explained. 

These results indicate that it is not possible to assert that an S 
has a given grade of general ability of apprehension, or even of 
visual apprehension: rather, we must state that he excels in the 
attentive observation of pictures, of drawings, of words, or of 
certain kinds of objects, etc. This confirms in an interesting way 
the general verdict of experimental work that mental ability is 
narrow and specific : here, for instance, we find that V is more than 
twice as efficient as G in the quick perception of groups of dots, 
while G is more than twice as efficient as V in the quick perception 
of irregular drawings. 

(3) The effect of practise is shown in Table 34. Here, each 
"period" represents the average of three exposures, usually one 
daily for three days. Inspection of these data gives little warrant 
lor the belief that systematic practise would enable an adult S 



Effect of Practise upon Visual Apprehension. Average for Thi 
Observers {Whipple) 


ee 


PERIOD 


1 


2 


3 


4 


5 


6 


T 


8 


9 




Pictures 

Nonsense . . . 
Drawings .... 

Poetry 

Objects 


6.6 
9.3 
6.6 
10.7 
5.6 


4.9 
10.6 

6.3 
11.5 

6.3 


5.9 
8.4 
5.0 
11.3 
5.9 


6.3 
10.8 

5.6 
10.8 

6.0 


6.9 
11.7 

5.0 
13.0 

5.9 


6.9 
10.6 

7.7 
12.5 

6.5 


6.5 
10.4 

6.5 
13.0 

6.4 


5.5 

8.9 
6.6 

11.7 


9.2 

5.7 



252 ATTENTION AND PERCEPTION 

markedly to improve his ability for quicic visual perception. The 
tests with dots do not lend themselves readily to quantitative treat- 
ment. The seeming improvement with drawings during the 6th 
period was due to the use of one very easy drawing in that group. 
There is some slight evidence of an improvement in reading poetry, 
which amounts roughly to the addition of one word, but this may 
be attributed to increased familiarity with the peculiar style of the 
poem in use. If any improvement can be inferred in the case of the 
objects-test, it must amount, on the average, to the addition of less 
than one object. 

What meager practise-effect is here to be detected is entirely 
explicable by increased familiarity with the material in use, and by 
the appearance of the little tricks or schemes of grouping men- 
tioned below. It is highly unlikely that this period of practise 
really trained the attention of the S's in such a way as to enable 
them to excel others in the quick observation of objects or inci- 
dents other than those used in the experiments. It is impossible 
to explain the marvelous exploits reported by Miss Aiken^ — one 
sample of which may be cited here. The column of numbers that 
we have mentioned (p. 247) was exposed by Miss Aiken for 3 sec. 
only; "the pupils were then asked but once to multiply the first 
number by two, to extract the cube root of the second, to square 
the third, to extract the square root of the fourth, to divide the 
fifth by two, to multiply the sixth by twenty-four, and to divide the 
seventh by four, and then to repeat the changed column, which 
they did as follows: 460, 9, 121, 6, 20,000, 384, 10."^ 

(4) A qualitative analysis of the data secured in this experiment 
shows that the efficiency in visual apprehension exhibited by any 
S will depend on the following: 

(a) Native capacity for concentrating attention in general. This is the 
factor which it is desired primarily to isolate and measure, but it is impos- 
sible to secure such a measurement until the other factors are measured or 
eliminated. 

' From correspondence with some of Miss Aiken's puoils, I infer that it 
was her class as a whole, and not any single pupil, that was able to accom- 
plish these feats. In other words, one pupil undertook one, another a sec- 
ond, another a third phase of the reproduction, etc. Even so the perform- 
ance is amazing. 

^ See Miss Aiken's book, pp. 30 ff . for other examples. 



TEST 25: SENSE OF VISUAL APPREHENSION 253 

(6) The degree of attention given at the exposure in question. In theory, 
each exposure is accompanied by S's maximal attention: in practise, this 
is not always secured. Tests in which S reports distraction must be thrown 
out. The effect of good preparedness on S's part may be illustrated readily 
by exposing test-cards without warning of their type; the consequent 
elimination of 'expectant attention' will reduce S's efficiency. 

(c) Individual capacity of S to attend to, and to assimilate, tlie particular 
type of material in use — drawings, nonsense syllables, etc. 

(d) The ease of assimilation of the particular test-card in use. Thus, an 
easy bit of poetry will increase the performance of all S's ; a drawing that can 
be named, however fancifully, can on this account be held longer and repro- 
duced better by most »S's. 

(e) Obstruction or distraction: Some feature in the object displayed, 
whether important or trivial, will often catch S's attention, interfere with 
his exploitation of the balance of the exposure field, and thus measurably 
reduce his performance. Thus, a misprint in a line of poetry, or the presence 
of some unusual word, will induce most /S's to reread the line, even at the ob- 
vious expense of their record. 

(/) Ideational type: Visually-minded S's hold drawings, pictures, and 
objects by their visual appearance, and are inclined to use visualization for 
the reproduction of at least portions of the nonsense syllables and poetry. 
Auditory-minded 5's hold verbal material by auditory imagery : if decidedly 
auditory-minded, like the author, they may also attempt to hold even pic- 
tures, drawings, and objects in so far as possible in auditory terms by using 
verbal formulations, names, etc., as cues for recall. 

ig) Restriction: S's performance is definitely conditioned by his volun- 
tary attempt to assimilate and reproduce either a large amount or a small 
amount of the material exposed. Thus, the nonsense syllables exposed are 
ten in number : by an effort, all ten may sometimes be read, but the result 
will be a poor reproduction of two or three syllables; if S confines his atten- 
tion to the first four syllables, he may read these twice, and succeed fairly 
often in reporting all four. Similarly, there may be voluntary restriction of 
attention to other types of material. 

{h) Grouping: As noted in Test 24, visual apprehension is greatly facili- 
tated by any device that permits the grouping of the constituent elements 
in the exposure-field. This factor, more than any other, gives us the explan- 
ation both of the individual differences and of the practise-improvement 
above mentioned. Thus, in the dot tests, the mass of irregularly arranged 
dots is, by most S's, arbitrarily rearranged (subjectively) into two, three, or 
sometimes four, groups of dots— each group containing three to six dots. 
Drawings are, similarly, often split up into component elements, and then 
recombined by a sort of analysis and synthesis. Sometimes this process is 
accompanied by the application of verbal symbols as tags for recall, e.g., 
"a rectangle, two peaks, and an arrow." For most *S's, this analytic-group- 
ing method turns out to be more effective than the 'steady stare" which 
they are prone to employ at first. 



254 ATTENTION AND PERCEPTION 



REFERENCES 



(1) Catherine Aiken, Methods of mind-training, N. Y. 1896. Pp. 75. For 
supplementary exercises, see her Exercises in mind-training, N. Y. 

(2) Life of Robert Houdin, the king of conjurers, by himself, Philadelphia, 
1859. (Ch. 14, p. 256.) 

(3) J. P. Hylan, The distribution of attention, in P. R., 10: 1903, 373-403 
and 498-533. 

(4) W. B. Pillsbury, Attention, London and N. Y., 1908. Pp. 330. 

(5) J. Quantz, Problems in the psychology of reading, in P. R. M. S., 
2: No. 1, 1897. 

(6) E. C. Sanford, A course in experimental psychology, Boston, 1895 
and 1898. Pp. 449. 

(7) G. M. Whipple, The effect of practise upon the range of visual at- 
tention and of visual apprehension, in J. E. P., 1: 1910,249-262. 

TEST 26 

Cancellation. — In order to measure degree of attention, several 
forms of test have been devised in which a continuous task is 
assigned under conditions such tliat maximal attention is demanded 
for the best work, and that any reduction of attention is reflected 
directly in the speed or accuracy of the work. Prominent among 
these tests is that which we shall term 'cancellation.' The essential 
principle is the crossing out of an assigned letter or letters, or word, 
or other symbol from a printed sheet. Investigators have modified 
the test in various minor details, have given it different names, and 
have used it for different purposes. Thus, its originator, Bourdon 
(4), used it with ten adults to measure "discrimination," Oehrn 
(7) proposed it, under the title "search for assigned letters," as a 
convenient test of attention for experimentation in individual 
psychology; Cattell and Farrand (5) introduced it into the series 
of tests of Columbia University students in the form of the "A- 
test" for "rate of perception," and Thorndike employed it later, 
together with what may be regarded as variations of it (the "o-f 
test," the "e-r test," and the " misspelled-word test") for various 
comparative studies, particularly for his examination of the mental 
traits of twins (12); Binet (3, 236 ff.) called it the "correction of 
proof" test, and used it to contrast the ability of intelligent and 
unintelligent children (as did Winteler, 14), to measure fatigue 
(as did Ritter, 8), and incidentally, to study tfieir capacity to 



TEST 26: CANCELLATION 255 

break and form associations; Miss Sharp (10), from whom the 
term cancellation has been borrowed, tried the test in her studies 
in individual psychology with Cornell University students; Vogt 
used cancellation to examine attention and distraction; Judd in 
his Manual (6), has classed the test among those devoted to dis- 
crimination reactions; the author has tried the test as a measure of 
fatigue, and also has sought to determine its correlation with class 
standing.^ 

The results of the cancellation test are conditioned in the main 
by three methodological factors — (a) the number of letters to be 
cancelled, (6) the kind of text or material employed, and (c) the 
duration of the test. 

(a) Letters cancelled. It is easily demonstrated that the ranks of a given 
number of S's will vary somewhat according as a few (1-2) or several letters 
(4-6) are to be cancelled. Where but one letter has been used, this has 
commonly been the letter a (Bourdon, Cattell and Farrand, Wissler, Thorn- 
dike, Sharp) or occasionally e. In cancelling more than one letter, we find 
that Bourdon tried at different times, a and i; a, r, i, s;a, e,l,t',OY a, e, I, t, 
0, k; Binet, a, e, d, r, s, also i, o, I, f, t, and a, e, r, o, s, m; Vogt, I, n, s; 
Winteler n, s, t, and I, m, r, s, t. 

It is Binet's contention that, when but one letter is cancelled, *S'stendto 
work with approximately equal accuracy, but with varying speed, whereas, 
when four or five letters are cancelled, they tend to work with approximately 
equal speed, but with varying accuracy; he, accordingly, arranges the test 
in one or the other of these ways, as he wishes to measure either speed or 
accuracy. As will be shown later, this assumption is not strictly justifiable. 

The cancellation of one letter is so easy that some investigators have tried 
other devices for complicating the task: Ritter, for example, had his *S's 
cancel every r with a vertical stroke and every article (in German texts) 
with a horizontal stroke, or, again, every s with a vertical and every preposi- 
tion with a horizontal stroke : his idea that these two assignments would be 
equally easy and could thus be used interchangeably was not borne out in 
j)ractise. Thorndiko has used still another variation: mark every wo7^d 
(in a Spanish text) containing both e and r, or both a and t. The same inves- 
ti gator has used a three-minute test in which misspelled words in a page of 
narration are cancelled as rapidly as possible. 

(6) Material. We may distinguish five kinds of material — (1) spaced 
prose, (2) unspaced prose, (3) disconnected words, (4) unregulated pied 
material, and (5) regulated pied material, with (a) unequal, or (6) equal, 
proportion of the constituent letters. 

' In an extended study of mental and physical tests upon 50 grammar- 
school children, the results of which have not yet been published in full. 



256 ATTENTI(3N AND PERCEPTION 

(1) Spaced prose is secured by taking any ordinary printed matter, but 
preference has been given to scientific (Binet) or philosophical (Sharp) 
texts, rather than to easily grasped material (Winteler). 

(2) Unspaced prose, as employed by Miss Sharp, is secured by having a 
page of concrete description, or of more abstract material, printed without 
capitals, spacing, or punctuation. The following lines will serve to illustrate 
two such texts: 

theshoresoftheislandwerecompletelyfringedwithbushesand 
greatcarehadbeentakentopreservethemastheyansweredasascreen 

theproblemofphilosophyhasbeenineveryagetodeterminethe 
relationbetweenbeingandthoughtbetweensubjectandobjecteveryphil 

(3) Disconnected words were used by Sharp only: the text is a series of 
sense words arranged in nonsense combination. 

(4) Unregulated pied material may be formed, after the fashion of Bourdon 
and Vogt, by printing a page of Hungarian, Finnish, or other little known 
foreign language, and omitting all capitals, punctuations, and combinations 
that suggest English words. The same material can be secured more simply 
by letting the printer set up a page of small letters picked at random from a 
pile of mixed type. 

(5) Regulated pied material has a distinct advantage over other forms of 
material, for in the latter it is impossible to know without laborious count- 
ing just how many of any given letter are found in the passage, and the same 
passage does not afford the same opportunity for the use of different letters. 
The texts which contain actual words, whether spaced or unspaced, also 



THE A-TEST 

OYKFIUDBHTAGDAACDIXAMRPAGQZTAACVAOWLYX 

WABBTHJJANEEFAAMEAACBSVSKALLPHANRNPKAZF 

YRQAQEAXJUDFOIMWZSAUCGVAOABMAYDYAAZJDAL 

JACTNEVBGAOFHARPVEJCTQZAPJLEIQWNAHRBUIAS 

SNZMWAAAWHACAXHXQAXTDPUTYGSKGVKVLGKIM 

FUOFAAKYFGTMBLYZIJAAVAUAACXDTVDACJSIUFMO 

TXWAMQEAKHAOPXZWCAIRBRZNSOQAQLMDGUSGB 

AKNAAPLPAAAHYOAEKLNVFARJAEHNPWTBAYAQRK 

UPDSHAAQGGHTAMZAQGMTPNURKNXIJEOWYCREJD 

UOLJCCAKSZAUAFERFAWAFZAWXBAAAVHAMBATAD 

KVSTVNAPLTLAOXYSJUOVYTVPAAPSDNLKRQAAOJLE 

GAAQYEMPAZNTIBXGATMRUSAWZAZWXAMXBDXAJZ 

ECNABAHGDVSVFTCLAYKUKCWAFRWHTQYAFAAAOH 



TEST 26: CANCELLATION 257 

interfere with different S's to variable extents by the tendency to the appear- 
ance of apperceptive processes, akin to reading. The first user of the can- 
cellation test, Bourdon, regretted that he had not made use of regulated 
pied material ; so, too, Vogt. This regulation may be of two forms. In the 
first, a single letter is chosen as a test letter and this is introduced a given 
number of times in chance order with other letters which occur less fre- 
quently. This arrangement is best illustrated in the so-called "A-test," 
which is here reproduced. It contains 100 A's and 400 other letters, 16 times 
each, and is printed in U-point capitals. 

The A-test has three disadvantages : it is not devised to permit the use of 
any letters other than A ; it does not lend itself easily to four-letter cancella- 
tion; in many instances, two or more A's are in juxtaposition, so that some 
S'a may see and cancel several at once. 

To avoid these difficulties, recourse may be had to the second form of regu- 
lation, viz : the use of each of the 26 letters the same number of times each. 
In constructing the forms which are prepared for this test, the printer has 
mixed together 100 types of each letter and set them in chance order, save 
where a given letter was repeated too closely. 

(c) Duration. It is preferable, whenever possible, to have all S's cover 
the same amount of material and to secure the quantitative record in terms 
of elapsed time. But, for group work, it is necessary to set a given 
time for all S's and to secure the speed record in terms either 
of extent of material examined or number of letters crossed. Most 
E's who have experimented with small groups have chosen the first method: 
the actual time expended upon cancellation has ranged from 1 to 20 min., 
or even several hours. At Columbia, 1 min. is allowed for the A-test, 2 min. 
for the a-t test, 3 min. for the misspelled word test. When working by the 
individual method, the A-test takes, on the average, about 95 sec. Miss 
Sharp's tests demanded from 3 to 4 min. ; Bourdon used 6 min. ; Winteler 
15 min. ; Binet found that by extending the time to 10 or 20 min., he could get 
signs of fatigue. When such long times are used, E may follow the time with 
the stop-watch and, at expiration of each minute, check with a small hori- 
zontal underlining mark, the point at which S is then working. It was 
Oehrn's idea that the cancellation test might be extended through several 
hours in order to analyze such factoi's as praise, fatigue, ennui, spurt, 
warming-up, etc. This has been partially done by Vogt, who worked for an 
liour or more at a time, in 10 min. periods with 5-min. intermissions. 

Four forms of the cancellation test are here described; the first 
two deal with the cancellation in a regulated pied text of one letter 
and of four letters, respectively; the third reproduces the word- 
cancelling tests, and the fourth the misspelled- word tests, as admin- 
istered at Columbia Universit}-. 



258 ATTENTION AND PERCEPTION 

A. Cancellation of a single letter 

Materials. — Printed form, containing 100 of each of the 2(J 
letters arranged in chance order.^ Stop-watch. Pencil. 

Method. — Whenever convenient, work with one S at a time. 
Place the forin before S, printed side down. Instruct him as fol- 
lows: "When I say 'ready,' turn over this sheet of paper, begin at 
the first hne, and mark every a^ on the page like this." (Exhibit 
for an instant another sample form, already marked, to be sure 
that S understands the instructions.) ''Mark as rapidly as you can, 
but try not to leave out any a's." Give the command — "ready." 
Start the watch when S glances at the first hne: stop it when he 
finishes the last line; record on the form the time, together with 
S's name, the date, and other needed items. 

If necessary to follow the group method, as in conducting class- 
room tests, it is a good plan to write a sample line on the black- 
board and show how the cancellation is to be done. Make sure 
that no S turns the paper before the signal, and that all start simul- 
taneoush^ All S's must cease work at the command "stop," and 
underscore horizontally the letter at which they were looking when 
this command was given. The exact time to be used must be 
determined by a few preliminary experiments; it should be such 
that the fastest S to be examined will not quite be able to finish : 
2 min. is to be generally recommended, since very few adults can 
finish within that time. 

B. Cancellation of four letters 

Material. — As before, using the form beginning zycu. 
Preliminaries. — With a typewriter, place at the top of each 
sheet the letters — q r s t? 

1 This form begins h-plg, etc. : if it is desired to repeat the test with the same 
letter on a new form, use the one beginning zmju. 

- The letter a is chosen merely because it has commonly been used. If it 
is desired to repeat the test with other letters, it would doubtless be pre- 
ferable to select a number which have been shown to be of nearly equal legi- 
bility. For this, one may recommmed m and u\ or the four letters, q, p, 
b, d. (SeeSanford, 8.) 

' Save for special purposes, the cancellation of four letters suffices as well 
as that of five or six to bring out the characteristics of the test. The letters 
g, r-, s, t are selected because they form, a combination fairly easily remem- 
bered, and embrace one letter projecting above, one projecting below the 
line, and two small letters. 



TEST 26: CANCELLATION 259 

Method. — As before, with the added explanation that the letters 
to be marked have been placed for reference at the top of the 
sheet. (E must, of course, also state the letters verbally before- 
hand.) The time will naturally be longer than before: 4 min. may 
safely be used in most group tests, as a competent adult takes 
nearly 5 min. 

C. Cancellation of words — the a-t and the e-r test 

Material. — Printed page from a Spanish text. 

Method. — Instruct S to mark with a horizontal stroke each 
ivord containing both a and t. Exhibit a sample page, or illustrate 
on the blackboard. Forewarn S that the words are in a foreign 
language. If the individual method can be followed, take the time 
for the whole sheet; if the group method is followed, allow 2 min. 

For a second test, use fresh sheets of the same text, but substi- 
tute e and r for a and /. 

D. Cancellation of misspelled words 

Material. — Two printed texts containing a large number of 
misspelled words. 

Method.- — Test each text separately. In each case, instruct S 
to mark with a horizontal stroke every word that is not spelled 
correctly. Take the time for the whole sheet, or allow 3 min. 

Treatment of Data. — In these four tests, wemeet the difficulty 
which often appears, of having two or more indexes of efficiency — 
in particular, one of speed or quantity of work done, and one of 
accuracy, precision, or quality of work done. For some purposes 
it is valuable to keep these indexes distinct, but more often it is 
desirable to unite them into a single index which shall express fairly, 
though perhaps -somewhat arbitrarily, ^S's net efficiency. 

If, as advised, we work by the individual method, the problem is simpli- 
fied, for the elapsed time yields a direct index of speed. If we work by the 
group method, we have two possible indexes of speed — the number of' 
letters marked, or the number of letters examined. In general, the latter is the 
safer index, since we have no certain guarantee, at least in the word tests, 
that the various portions of the text are of equal opportunity or equal diffi- 
culty, and cannot, for example, assume with certainty that the marking of 
30 letters or words indicates half-again as much ability as the marking of 20. 



260 ATTENTION AND PERCEPTION 

The conversion of the speed and accuracy indexes into a single index has 
been attempted in various ways. Binet, as we noted, suggests that accur- 
acy may be ignored when one letter is cancelled, and speed when several are 
cancelled. Cattell and Fullerton (5) propose to convert accuracy to speed 
by adding to the obtained time, the time that would be required to mark the 
letters omitted or wrongly marked — this increment being determined by 
simple proportion, on the basis of the actual time and the number of errors, 
but this correction has often been omitted in the use of the A-test. (Neither 
Vogt nor Winteler considered accuracy in ranking their S's, even though 
3 and 5 letters were to be cancelled.) Miss Sharp, on the other hand, con- 
verts speed to accuracy on the assumption that "in a given individual 
maintaining a constant degree of attention while doing a piece of work, 
the percentage of error is inversely proportional to the time taken for the 
work." While these methods seem theoretically justifiable, the actual 
reduction is very large in the case of some S's. Possibly an empirical cor- 
rective formula might be experimentally determined. 

Ritter calls attention to the prime necessity of making clear to »S at the 
outset whether it is speed or accuracy that is the more desired. This em- 
phasizes once more the necessity of having a standard formula for the 
instruction of S's and of using it without variation. Ritter's own system 
of correction was as follows: add 1 for the omission of 1 line, 2 for the 
omission of 2 lines, 3.5 for 3 lines, 5 for 4 lines, 7 for 5 lines, and 2 for each 
subsequent line. 

The following treatment is advised for the letter-cancellation 
data. When possible, rank speed in terms of time; when this is 
not possible, rank speed in terms of letters examined (ground 
covered). 

Compute the index of accuracy according to the formula 

c — w 
A = 



c -^ 
in which A = the index of accuracy, 

=the number of letters erroneously omitted, 

c =the number of letters crossed, 

w =the number of letters wrongly crossed. 

To compute a single index of efficiency (net efficiency), use the 
formula 

E =SA, 
in which E =the desired efficiency index, 

S =the speed index (ground covered), 
A =the accuracy index, 



TEST 26: CANCELLATION 261 

or the formula 

^- A 

when N =the speed index (in terms of time). 

To illustrate : a 12-year boy in the §/-s/-test covered 825 letters, crossed 40 
(including 2 iv's), and omitted 78. By the formulas just given, we find 8 = 
825, A = .322, E = 266. This instance is characterized by e.xtreme inaccu- 
racy, so that the degree of penalization seems perhaps over-great, but it rep- 
resents as fair a method of computing net efficiency as can at present be 
devised. 

It is often of interest to keep records of the number of omissions 
for each letter, as in this way, one may get comparative estimates 
of their difficulty. 

For the word-cancellation, similar methods may be pursued : 
when the test is administered by the time-limit method, efficiency, 
for the sake of simplicity, may be taken in terms of the number of 
words marked, with a deduction of 2 for each wrongly marked 
word.^ 

The rank in the misspelled word test may, similarly, be best 
computed in terms of time, with a reduction for errors as described 
for the cancellation of letters.^ 

Resuits AND CoNCLUsiON3^. — (1) Dependence OH age. There is 
imdoubtedly a general improvement with age both in speed and 
accuracy of cancellation, but we have no elaborate comparative 
study of different ages. Wissler's results for the ^-test (15) 
show that Columbia seniors better their freshmen records: in 35 
cases, there was an average reduction in the time from 105.4 to 
88.9 sec, and in errors from 4.7 to 1.6. 

(2) Dependence on sex. Wissler found that women surpass men 
in the A-test: 270 men averaged 100.2 sec. with 2.2 errors; 42 
women averaged 91.2 sec. with 3.0 errors. 



' This method is followed by Thorndike, who found such errors only in 
one of ten papers on the average. 

^ Thorndike neglected errors in this test, though they occurred in about 
one-third of the papers. 

^ Unless otherwise stated, these results are based on the letter cancel- 
lation tests. For illustrative records of the other tests, consult Thorn- 
dike (12, or 11, pp. 47-9.) 



262 



ATTENTION AND PERCEPTION 



(3) Dependence on letter cancelled. According to Bourdon, let- 
ters whose form is simplest are of tenest omitted ; with the letter o, 
6 to 10 times as many errors were made by his 5's as with the letter 
e, but the author's comparative tests with the letters c and o do not 
substantiate these conclusions fully. Table 35 shows that in 40 
consecutive tests, grouped by tens, o is distinctly easier to cancel 
than c, save in the first group ; it may therefore be expected that it 
is easier to cancel than e, which, in practise, is often confused with 
c. In the qrst-tesi, 50 boys committed errors of omission as follows : 
s, 337; t, 561; r, 653; and q, 718. Here there is no relation whatso- 
ever with legibility, since s belongs to the group of relatively illegi- 
ble letters, and q to the group of very legible letters (Sanford, 9). 
We may conclude that when school children cancel these four let- 
ters in one test, it is the least often used letter that suffers most 
from omission. 



TABLE 35 
Effects of Letters and of Fatigue on Cancellation (Whipple) 



— :1'kT 


m.v. 


SECOND 

TEN I '"•"• 


THIRD 

TEN 


m.v. 


FOURTH 

TEN 1 "'■"• 


AVER- 
AGE 


c 93.12 

94.06 


5.36 
4.93 


1 91.04 
86.28 


5.73 
1.42 


89.86 
82.64 


3.0 
3.4 


96.64 
87.52 


4.69 
3.46 


92.66 
87.62 


Average 93.59 




88.21 


j 86.25 




1 92.08 





(4) Dependence on the form of material. The effect of the material 
used for cancellation is indicated by the results of Bourdon and of 
Sharp. Bourdon found that a change in size of type from one in 
which the small letters were 1.75 mm. high to one in which they 
were 1.25 mm. high made httle difference; if anything, the smaller 
type proved better. The same investigator found that more letters 
are cancelled in nonsense than in sense material. Sharp found that 
the use of unspaced, in comparison with spaced, material reduced 
the speed, but also reduced the errors. The average time for seven 
aS's for a spaced text was 190 sec, for an unspaced 219 sec, and the 
average percentage of error was 9.6 and 4.58, respectively. The 
faster speed and poorer quality of work done with ordinary prose 
is plainly due to the tendency for the rise of meaning to act as a 



TEST 26: CANCELLATION 263 

distraction to the process of cancellation; the latter requires atten- 
tion to individual letters, whereas the former (ordinary reading) 
proceeds naturally by the assimilation of words as wholes. As 
will be noted below, most S's do not 'read' the text when can- 
celling letters in pied material. 

(5) Dependence on number of letters to he cancelled. According 
to Bourdon, an increase in the number of letters to be cancelled 
causes a progressive decrease in the extent of material examined, 
but approximately the same lyjmber of letters is cancelled in a 
given time. This conclusion may be accepted as generally valid, but 
much depends upon the arrangement of the material. Bourdon is 
of the opinion that aS's that are accurate in cancelling one, are also 
accurate in cancelling several letters. The author's tests confirm 
this generalization in the main, as they show a value for this (correla- 
tion of +0.38 (Table 37). With regard to speed. Bourdon merely 
states that some individuals slow in marking one letter prove fast 
in marking several; my results indicate, however, that the corre- 
lation between one- and four-letter efficiency is greater in the case 
of speed (+0.49) than in the case of accuracy (Table 37). 

(6) Relation of speed and accuracy. Binet, as previously noted, 
assumes that speed tends to be equa'ized in marking four letters, 
accuracy in marking one letter. My tests with 50 boys (Table 36, 
last column) show that, while there is a tendency in this direction, 
it is not sufficiently pronounced to warrant the neglect of either 
speed or accuracy in estimating efficiency. In other words, the 
variation in speed is proportionately less in marking four letters 
than in marking one letter, and the variation in accuracy is pro- 
portionately less in marking one letter than in marking four letters, 
but there is nothing approaching equalization of either factor. 

TABLE 36 

Averages and Variations in Cancellation Tests (Whipple) 



e 


Speed 


702 


193 


27 


q, r, s, 1 


Speed 


811 


177 


22 


e 


Accuracy 


89.6 


8.0 


9 


q, r, s, t 


Accuracy 


63.1 


11.4 


18 



2()4 



ATTENTION AND PERCEPTION 



Cattell and Farrand state that some aS's are slow and accurate, 
some slow and inaccurate, some fast and accurate, some fast and 
inaccurate. Since, however, an S that works very fast presumably 
tends to work less accurately, we may expect to find indications of 
an inverse correlation between speed and accuracy, and this is the 
case. Wissler's relatively easy ^-test gives an inverse correlation 
(r = —0.28). In the author's tests, the cancellation of one letter is 
harder than that of the ^-test, and the cancellation of four letters 
is still harder; in consequence, we find inverse relations of —0.37 
and —0.64, respectively (Table 37). In the case of 30 Cornell 
University students, speed and accuracy were found similarly 
inversely related, but by a lower coefficient (r= —0.48, Table 37). 

TABLE 37 

Correlations in Cancellaturn Tests: 50 (Irdninidr-Srhool Boys (Whipple) 



I'lHST MEMBER 



SECOND MEMBEK 



Speed, one letter 

Speed, four letters 

Speed, four letters 

Speed, one letter 

Accuracy, one letter 

Speed, one letter 

Accuracy, one letter 

Net efficiency, one letter 



Accuracy, one letter. . . 
Accuracy, four letters. 
Accuracy, four letters. 

Speed, four letters 

Accuracy, four letters. 

Class-standinp; 

Class-standing 

Class-standing 



Speed, four letters [('lass-standing. 

Class-standing, 
(^lass-standing. 



Accuracy, four letters 

Net efficiency, four letters. . 

Net efficiency, one letter Word-building (Tost 47) 

* This correlation refers to .30 University students. 



-0.37 
-0.64 
-0.48* 

0.49 

0.38 
-0.40 

none 
-0.32 
-0.40 

0.39 
-0.09 

none 



(7) Dependence on practise. Practise increases efficiency in all 
cancellation tests, as is illustrated in Tables 35, 39 and 40. Whether 
this practise-effect concerns only the letter used, or extends to all 
letters, cannot be stated until a series of equivalent letters has 
been determined by preliminary tests. Continued practise with the 
same letters almost doubles speed, and raises accuracy to a maxi- 
mum. The letters are not held in mind by conscious effort but 
recognized quasi-automatically, and the whole process becomes 
unexpectedly simplified. 



TEST 20: CANCELLATION 265 

(8) Dependence on fatigue. The experiments of Bourdon, Binet, 
and Ritter show that cancellation is affected by fatigue, which 
reduces accuracy, rather than speed — a result in accordance with 
what we know of the effects of fatigue on other forms of mental 
activity. It follows that the cancellation of four or more letters is 
better adapted than the cancellation of one letter for testing fa- 
tigue. If but one letter is cancelled, practise and warming-up may 
easily conceal fatigue, as is shown in the author's continuous tests, 
extending over two hours and characterized by marked subjective 
fatigue (Table 35). 1 

In his examination of fatigue, ]3inet compared the first and 
second half of a 20 min. test, and found that his *S's had made 54 
errors in the first, and 95 in the second, 10 min. Ritter was suc- 
cessful in 8 of 10 trials in getting indications of fatigue in school 
children by his form of the cancellation test: Table 'SS gives a 
sample series of errors. 

TABLE 38 
PJfferlK of Fatigue on CancelUition (Ritter) 



PREVIOUS SCHOOL EXERCISE 



! 37 

• Greek 94 

10. 10 u. m Pause for Vespers 78 

12 111. Livy and ('hemistry 84 

(9) The correlation between cancellation and intelligence is obscure. 
Wissler found no correlation between the ^l-test and class standing. 
Binet's results are gained from four different series: in Series 1 
(cancellation of five letters), the intelligent and unintelligent 
showed little difference in speed, though the former increased their 
speed more in the second half of the test; the unintelligent, how- 
ever, made four times as many errors. In Series 2, conducted 15 
days later, the unintelligent equalled the intelligent in speed, but 
were still inferior in accuracy. In Series 3, a sudden change was 

' It may be stated, however, that some three or four tests which followed 
the fourth group, but which are not included in the table, indicate a distinct 
increase in time required, e.g., from 85-95 to 106-108 sec. The quality of the 
work showed no progressive changes. 



266 



ATTENTION AND PERCEPTION 



made in the letters assigned; this reduced the speed of all S's more 
than one-half, and the intelligent, rather oddly, made more errors 
than the unintelligent. Binet explains this on the ground that they, 
the intelligent, had established their associations more strongly in 
previous series.^ In Series 4 (20 min., 6 letters, two of them new), 
the speed was about equal for the two groups, but the unintelligent 
made more errors. 

Winteler's gross results (Table 39) indicate the superiority of his 
intelligent children, but when his *S's are ranked individually, two 
of the four unintelligent are foimd to be superior to some of the 
intelligent. Similarly, the unintelligent seemed as capalile as the 
others in adapting themselves to the change from crossing three to 
crossing five letters, so that Winteler concludes that one cannot, on 
the whole, discern any inferiority on the part of the unintelligent 
with respect to the number of letters cancelled, to their quickness of 
adaptation, or to the steadiness with which attention is maintained 
within the series. It is to be regretted that Winteler did not take 
any account, direct or indirect, of the number of errors. 

TABLE 30 

Relation of Arrnn/,: \ umber of Letter.^ Cannllcl to I ntcUi(icncc {Winteler) 





I'lRST 
DAY 


nsl 

SECOND j 
DAY 


BOTH 


FIRST 
DAY 


I m r s t 

SECOND 
DAY 






LETTERS 


BOTH 


ALt 
TESTS 


Intoll 

[TnintoU 


277 
255 


329 
.303 


(506 

558 


312 
248.5 


414 
326,5 


726 
575 


1326 
1133 



The author's own tests are summarized in Table 37 : it is evident 
that there is an inverse relation ( — 0.40) between speed and class 
standing; that, when one letter is cancelled, there is no correlation, 
but when four letters are cancelled, there is a direct correlation 
(0.39) between accuracy and class standing: that, when accuracy 

' It would be interesting to see whether, in such a test, the intelligent 
would surpass the unintelligent, provided the latter had, by added practise, 
been brought to an equal state of proficiency before the change of letters. 
In accordance with Binet's thesis that intelligence is indicated primarily 
by readiness to adapt oneself to a new situation, we should then expect the 
unintelligent to make the greater number of errors. 



TEST 26: CANCELLATION 267 

and speed are conjoined in a single index (net efficiency), there is a 
definite inverse correlation for one letter, and a possible inverse 
correlation for four letters, between such efficiency and class 
standing. In other words, the best pupils work more slowly at 
the cancellation test ; if four letters are cancelled, this slower speed 
has its reward in a relatively high degree of accuracy. 

(10) Other correlations. Wissler found no correlation between 
cancellation and reaction-time to sound, and only a low correlation 
(0.21) between the A-test and a test of quickness in naming colors. 
The same investigator found that weak eye-sight was conjoined 
with inaccuracy in the A-test, but that the reverse was not true.^ 
Thorndike found a correlation between twins of 0.73 in the ^-test, 
0.75 in the a-t and e-r tests and in the misspelled word test. 

The author's grammar-school boys showed no correlation be- 
tween net efficiency in cancelling one letter and the word-building 
test. 

Aikens, Thorndike, and Hubbell found no correlation between 
quickness in the misspelled word test and quickness in the e-r 
test, and a correlation of 0.16 (8th-grade pupils) to 0.25 (5th-grade 
pupils) between accuracy in these two tests, as measured by num- 
ber of words or letters marked per line. The correlation of efficiency 
in the e-r test and in addition and association tests was also found 
to be slight or none, but efficiency in misspelled words and in 
addition and associations tested was correlated by 0.50. 

(11) Dependence on the form of movement. Bourdon's descrip- 
tion of the process of cancellation seems to imply that the examina- 
tion of the line is interrupted during the process of cancelling 
itself. It is doubtless true that the movement of reaction does 
interfere sometimes with the process of perception and recognition. 
Vogt has attempted an experimental analysis of this interference 
by comparing the amount of ground covered in the usual method 
and the amount of ground covered when the assigned letters are 
simply recognized but not marked.^ 

' In certain series conducted by the author with a University student to 
test the relative values of various letters, the net result of two months' work 
was to indicate the probability that the student had astigmatism! — an infer- 
ence which was confirmed by the oculist. 

2 There is here no check upon accuracy : it would seem better to let S name 
the letters as fast as recognized, or at least utter some simple sound or tap 
his finger at each recognition as suggested above. 



268 



ATTENTION AND PERCEPTION 



He found that, in his own case, the marking slowed the speed of 
the performance as a whole by at least 15.8 per cent., in the case of 
another, less practised S, by the astonishing amount, 42.3 per 
cent. If these conclusions are generally valid, we shall have to 
admit that the apparently 'mechanical' phase of the cancellation 
work may easily be the determining factor in the individual dif- 
ferences which the test may reveal, and this will alter radically 
our conception of the nature of the test. 

But, in the author's opinion, Vogt's results are so warped by 
the intrusion of practise and warming-up (Anregung) as to be in- 

TABLE 40 
Effects of Different Methtxh of 'Reaction' in qrst-Test (Whij^ple) 



NUM- 
BER 


TIME ELAPSED SINCE 
PRECEDING TEST 


METHOD OP REACTING 


SPEED IN 

SEC. 


OMITTED 
OUT OF 199* 


1 




Finger tapping 


283 


? 






2 


10 minutes 


Electric key 


246 


3 


3 


10 minutes 


Actual marking 


207 


3 


4 


15 hours 


Electric key 


220 





5 


5 minutes 


Actual marking 


193 


4 


6 


5 minutes 


Mere recognition 


197 


? 


7 


2 liours 


Electric key 


237 


1 


8 


1 hour 


Actual marking 


184 


4 



• In the test in use, there were only 49 s's, owing to a printer's error. 

conclusive. They certainly do not accord with the results in Table 
40, which represent the author's tests upon himself by several 
variant methods. 



In this work, the same text and the same letters were employed in eight 
trials on two days. Test 6 was in accordance with Vogt's series in which S 
merely recognizes the letters, and executes no movement of reaction. In 
Test 1, the finger was lifted slightly as each letter was recognized. In Tests 
2, 4, and 7, this movement was changed into a simple tap upon an electric 
key, which was connected to an electric recorder: this device enables one 
to record the total number of movements of reaction and hence to measure 
accuracy in terms of omissions, while the movement is so familiar and simple 
as to be virtually negligible. In the remaining tests, the letters were can- 
celled by pencil strokes in the regulation manner. 



TEST 26 : CANCELLATION 269 

It is evident that when two or three tests are administered in 
close succession, there tends to be improvement due to practise 
and warming-up, especially the latter. If the process of marking 
delayed the performance by any appreciable amount, we should 
expect Test 6 to be shorter than Test 5, and it would be difficult to 
account for the minimal time shown in Test 8. Moreover, the 
author can testify from introspection that there is no conscious 
delay introduced by the movement of cancelling itself. It is 
quite possible that some S's may be delayed, however, by the can- 
celling, and it would be profitable, whenever time permits, to inves- 
tigate, by appropriate tests, the nature and extent of this retarda- 
tion in speed. 

(12) Qualitative analysis. Most S's do not pronounce the letters 
of the text, as is shown both by introspection and by the fact that 
a greater number of letters can be examined than could be read 
over silently in the same period, e.g., 1876 and 1086, respectively 
(Bourdon). The letters to be cancelled, however, are often men- 
tally pronounced by S, especially if four in number, in order to keep 
them in mind. Attention is then arrested by the sight of' the 
assigned letters, which are recognized either visually or by inner 
pronunciation. 

The most common error is that of omission. When four letters 
are marked, S often temporarily forgets one or more letters. Less 
often, S makes no marks at all for limited parts of a line, or even for 
whole lines. The latter defect is, in the author's experience, char- 
acteristic of either very young, or very careless S's. 

Adults may hit upon the device of traversing every other line 
from right to left; this seems to economize time and to insure at 
least as great accuracy. 

REFERENCES 

(1) H. Aikens, E. Thorndike, and E. Hubbell, Correlations among per- 
ceptive and associative processes, in P. R., 9: 1902, 374-382. 

(2) A. Binet, Attention et adaptation, in A. P., 6: 1900, 248-404. 

(3) A. Binet, L'etude experimentale de I'intelligence, Paris, 1903. Pp. 
309. 

(4) B. Bourdon, Observations comparatives sur la i-econnaisance, la dis- 
crimination et I'association, in Rev. philos., 40: 1895, 153-185. 

(5) J. Cattell and L. Farrand, Physical and mental measurements of the 
students of Columbia University, in P. R., 3: 1896, 618-648. 



270 ATTENTION AND PERCEPTION 

(6) C. Judd, Laboratory manual of psychology, N. Y., 1907. Pp. 124. 

(7) A. Oehrn, Experimentelle Studien zur Individualpsychologie; in 
P. A., 1: 1896,92-151. 

(8) C. Ritter, Ermiidungsmessungen, in Z. P., 24: 1900, 401-444. 

(9) E. C. Sanford, The relative legibility of small letters, in A. J. P., 1: 
1888, 402-435. 

(10) Stella Sharp, Individual psychology: a study in psycliological 
method, in A. J. P., 10: 1899, 329-391. 

(11) E. L. Thorndike, An introduction to the theory of mental and 
social m.easurements, N. Y., 1904. Pp. 210. 

(12) E. L. Thorndike, Measurements of twins, in Archives of Phil., Psych, 
etc., No. 1, Sept., 1905 (Columbia Contrib. to Phil, and Psych., 13: No. 3). 
Pp. 64. 

(13) R. Vogt, Ueber Ablenkbarkeit und Gewohnungsfahigkeit, in P. A., 
3: 1901, 62-201. 

(14) J. Winteler, Experimentelle Beitrage zu einer Begabungslehre, 
E. P.,2: 1906, 1-48, 147-247. 

(15) C. Wissler, The correlation of mental and physical tests, P. R. M. S., 
3: No. 6, 1901. Pp. 62. 

TEST 27 

Counting dots. — This test was devised by Binet (1) and employed 
by him and later by Winteler (2) in their comparative studies of 
intelHgent and unintelligent children in order to measure the degree 
of attention. The problem set before S is that of counting a 
number of clots which are arranged in an irregular group or in lines 
of varying length and spacing^ When this work is attempted with- 
out the aid of pointer or pencil to keep the place, it is distinctly 
difficult and necessitates active concentration, but by selecting 
different arrangements of dots, this difficulty can be graded to suit 
S's of different degrees of development, and comparative scales 
of ability or norms for given arrangements of dots may presumably 
be established for each age. 

Material. — Stop-watch. Two sets (in duplicate) of 27 printed 
test-cards. 

These cards are numbered in the upper left-hand corner in accordance with 
the following plan : Cards A 1 to A 10 contain rows of dots with uniform spac- 

' The test evidently has similarity with the dot-counting under 3 sec. 
exposure (Test 25), but the removal of the time restrictions and the increase 
in the number of dots make the conditions quite different : here it is the degree 
rather than the range of attention that is primarily to be measured. 



TEST 27: COUNTING DOTS 



271 



ing (for each card) : Cards Ba 1 to Bd 4 contain lines with groups of 2, 3. 4 
or 5 dots each in which the spacing within the groups and between the 
groups varies as indicated in Table 41 : Cards C 1 to C 5 contain 5 arrange- 
ments of dots in irregular clusters. These three kinds of material reproduce 
those found to be of value by Binet and Winteler. The dots, like Winteler's, 
are 1.5 mm. in diam.' The 'A' cards were used by both experimenters, the 
'B' cards by Winteler only, the 'C cards by Binet only. The term 'points' 
in the Table refers to the printer's point or typographic unit: one point is 
1/72 inch. 

TABLE 41 



Specifications for 


Test-Cards Used in Dot-Counting 




Card Number 




Al 


A2 


A3 


A4 


A5 j A6 


A7 


A8 


A9 AlO 


Points in Spacing 

Number of Dots 




-.|20i 
. . 13 


19 
15 


12 
14 


10 

17 


8 1 5 
21 27 


4 
29 


3 
45 


3 1 3 
52 60 


Card Number 


Bal 


Ba2 


Ba3 


B. 


Bbl 


Bb2 


Bb3 \ Bb4 


Points within Groups . . 
Points between Groups 
Number of Dots 


6 
18 
45 


6 

18 
47 


6 
18 
55 


6 
18 
52 


1 ^ 
1 12 

j 50 


4 
12 

64 


4 

12 
70 


4 
12 
64 


Card Number 


Bel 


Bc2 


Bc3 


Bc4 


Bdl 


Bd2 


Bd3 Bd4 


Points within Groups. . 
Points between Groups 
Number of Dots 


3 

9 

70 


3 
9 

j 73 


I 

81 


3 

9 
90 


3 
15 
65 


3 

15 
75 


3 
15 

70 


3 
15 

72 



Card Number and Number of Dots: CI, 50; C2, 48; C3, 49; C 4, 54; C5, 57. 

Method. — Make the tests in the order indicated by the card- 
numbers. Instruct *S: "P'ind the total number of dots on this 
card: count aloud, in any way you wish (that is, by ones, twos, 
threes, etc) ; work as rapidly as you can, but try particularly to 
get the number right." The emphasis is thus placed on accuracy 
rather than upon speed. E should record aS's time, but without the 
latter's knowledge. He should also keep before him a duplicate 
of the card upon which 8 is working and should note thereon /S's 
method of grouping, in order to discover whether he counts always 
by ones, or always by twos, etc., and whether he accommodates 



' Binet found that <S's with poor eye-sight had difficulty with the test when 
the dots were 1 mm. in diam. 



272 ATTENTION AND PERCEPTION 

himself to the objective grouping of the 'B' cards. (*S's attention 
should not, of course, be called b}/ E to the grouping in these cards.) 
E should also record the magnitude of the error and its nature — 
whether overestimation or underestimation- — but should not com- 
municate this information to S. 

Treatment of Results. — Binet and Winteler both ranked *S's 
merely in terms of accuracy and put no time-limit upon their per- 
formance. It would seem possible, after some experience, to dis- 
cover the relation between speed and accuracy, and possibly to 
make use of a corrective formula as in the case of other tests 
where these tAvo factors appear, e.g., the Cancellation Test (No. 
26). The errors are to be counted simply by subtracting the given 
from the true number, e.g., 62 for 65 represents 3 errors. 

Results. — (1) Many S's have a constant error, but this may be 
either an error of overestimation, or an error of underestimation.^ 

(2) Winteler found that some S's always counted by the same 
number, i.e., used the same increment in adding, as "one, two, 
three, four," etc., or ''two, four, six, eight," etc. When the change 
was made to the ' B ' material, he found that all three of his bright 
children and one of the dull adapted their counting to the objective 
grouping, whereas the rest of the dull children continued for the 
most part to employ the form of counting (almost invariably by 
ones or by twos) that they had adopted in the ' A.' cards. 

(3) In examining the relation between dot-counting and intelli- 
gence, Binet concludes that, although the test exacts a high degree of 
attention, the outcome depends more upon /S's care than upon his 
intelligence. His results were confused by the presence of one 
bright child with poor eye-sight : when this case is eliminated, the 
intelligent children are found to make fewer errors than the unin- 
telligent: in one series the relation is 13 to 19, in another 16 to 24; 
the chfference, as in many other tests, tends to lessen with practise. 

Winteler likewise found the bright children, as a group, more 

1 No attempt has been made to analyze the conditions under which these 
constant errors appear; they might conceivably be due in part to illusions 
of filled and empty space, in part to individual differences in method of 
keeping the place in the line, in part to temperamental attitudes (over- 
cautiousness, careless haste, etc.). This test, like many others, has not been 
subjected to careful introspective analj^sis by trained adults. But critical 
qualitative study of this sort is as desirable for the intelligent employment 
of any test as i.s the mere accumulation of quantitative results. 



TEST 28: READING 273 

accurate, and also more rapid, than the dull children, but there 
were individual exceptions. The average for 10 series on each of 
two days were: errors, bright 8.33, dull 17.25; time in sec. per 10 
dots, bright 4.97, dull 6.30 — a suggestion that the tendency to 
inverse relation of speed and accuracy may not be so clearly evident 
as in many other tests. The difference in capacity of the two 
groups becomes striking, however, when the 'B' type of material is 
employed, because the unintelligent, as already noted, fail to adapt 
themselves to the objective grouping and make a large number of 
errors (79.75 to 9.00 of the intelligent). 

(4) The outcome of the test is not affected by general ability in 
arithmetic; some of Winteler's S's who did poorly had good grades 
in arithmetic. 

REFERENCES 

(1) A. Binet, Attention et adaptation, in A. P., 6: 1899 (1900), 248-404. 

(2) J. Winteler, Experimentelle Beitrage zu einer Begabungslehre, in 
E. P., 2: 1906, 1-48, 147-247. 

TEST 28 

Reading complicated prose. — Reading, like counting, is a form of 
perceptual activity that has been proposed as a means for measur- 
ing attention. In reading, as in counting (Test 27) , the process has 
been complicated in some manner in order tliat the increased diffi- 
culty may exact a higher degree of attention and so furnish a better 
opportunity for the study of individual differences. Miss Sharp, 
for instance, followed this plan when she sought to test degree of 
attention by requiring *S's to read two texts (a page of concrete 
description and a page of abstract exposition), which were printed 
without capitals, punctuation, or spacing. 

^In the present test, this plan has been extended, first by printing 
the complicated text backward, as well as without spacing, and 
second, by adding a test-sheet of similar subject-matter and identi- 
cal length, but of regular form, in order to supply a check-test of 
maximal speed of reading under normal conditions. 

Materials. — Two printed texts: (a) a page of prose in regular 
form, (b) a page of equivalent, but ' complicated' prose. Stop- 
watch. 



274 ATTENTION AND PERCEPTION 

Method. — The regular text (a) is used first. E gives the lollow- 
ing directions. "When I say 'now, ' I want you to read this aloud, 
just as fast as you can without making mistakes." E records the 
time; also, if desired, the number of errors. He does not, however, 
correct *S^'s errors in this part of the test.^ 

In using the reversed and unspaccd text (6), E's directions are: 
"When I say 'now,' read this aloud as fast as you can without mak- 
ing mistakes. You will' find this page more difficult than the one 
you have just read, because you will have to begin here in the lower 
right-hand corner and read it backward, and because this page is 
printed without any punctuation or capitals and without spaces 
between the words. I shall not give you any help, but if you make 
a mistake, I shall stop you, and ask you to correct it." 

E follows aS's reading upon a duplicate text. He records the time 
for the entire reading, and by glancing at the watch at every pause 
in the reading, he notes upon the duplicate text at the points con- 
cerned, the time in sec. consumed by S at these pauses. These 
notations should be made for every pause of 5 sec. or over. In case 
*S pauses for 30 sec. at any jioint, E then supplies for him the word 
or phrase which he needs to continue his work. 

To secure accuracy, E must correct every error in *S's reading, 
even slight errors, such as singular for plural forms, etc., and he 
must especially avoid the temptation to assist aS whenever he halts, 
save for the 30 sec. halts, as just stated. He m.ist notify *S of each 
error, as it occurs, by simply interjecting 'no,' and must indicate its 
place b^^ repeating the two or three words just preceding it. For 
example, if S reads: "they were all alike in tone," E interrupts 
with : "No ! — all alike in? — " S corrects himself : " all alike in one 
respect," etc. 

Variations in JVIethod. — In order to measure, and to be ab'e to 
allow for, individual differences in maximal rapidity of articula- 
tion, E may require aS' to reread the normal text four or five times, 

' With most adult, the errors are few in nuiulxn' and trivial in nature. To 
attempt to correct them would render it impossible to measure the speed of 
reading. If the errors are numerous, E may, however, ask S to reread 
the te.xt, this time without making a single error, hut still as fast as possible. 
The slight advantage that iS gains by knowing tlic subject-matter is of lit- 
tle moment compared to the false advantage that he has gained by hurrying 
liis reading so fast as to commit numy^errors. 



TEST 28: READING 



275 



or until the subject-matter is thoroughly familiar and further repe- 
tition fails to reduce the time. A brief rest-pause should follow each 
trial to avoid cumulative fatigue. Another method is to test S's 
time for counting aloud to 50 at maximal speed, though here it is 
often more difficult to check or control S's tendency to gain time l)y 
slurring or otherwise mutilating the words he pronounces. 

Results.— (1) The results obtained from a limited application 
of the reading test are summarized in Table 42, in which three 
groups of S's are represented — (a) five dull children aged 12.5 to 
16.75 years, (h) five bright children aged 10.33 to 12.75 years, and 
(c) 26 students in university and summer school classes — including 
two university instructors. 



Results of Reading Tests, in Sec. (Whipple) 





READING rORW.\RD 


HEADING BACKWARD 


j 


Aver. 


M.V. 


Mm. 


Max. 


Aver. M. V. 


Min. 


Max. 


Dull Children 5 116.4 
Bright Children ,5 .100.0 
University Students 26 73.3 


19. 
11.6 

8.5 


101 

85 
47 


169 

125 
100 


1061. 291 
544.4 167.2 
320. 100. 


814 
490 
125 


1500 
910 
755 



'This time is estimated from the amount of the text covered la 10 minutes. 



(2) A comparison of the performance of the bright pupils with 
mature students shows that age exercises an appreciable reduction 
in the time needed to read prose aloud, particularly when the task 
is artificially complicated. 

(3) A comparison of the performance of the dull and the bright 
children of approximately the same school grades shows the clear 
superiority of the bright pupils, despite the fact that they are some 
two years younger than the dull pupils. Here, again, the dif- 
ference is accentuated in the comphcated text. 

(4) Individual differences are more pronounced when the 
reversed text is used. 



276 ATTENTION AND PERCEPTION 

The coefficient of variability, for example, in the group of adults is approx- 
imately 11 per cent for forward, as contrasted with 33 per cent for 'back- 
ward' reading. 

The actual range of performance is also surprisingly large. Thus, in the 
adult group, the quickest backward reading is only 1/6 as long as the slowest 
backward reading. Miss Sharp's seven S's showed even greater individual 
differences — ranging from 143 to 900 sec. for concrete, and from 125 to 405 
sec. for abstract texts. When it is remembered that her »S's were all college 
students in advanced classes, the variability in performance seems unex- 
pectedly large, and it is hard to understand Miss Sharp's declaration: "We 
had expected to discover individual differences of much more definite char- 
acter and much greater amount." 

(5) The speed of reading the complicated text correlates in a 
rather high degree with the speed of reading the normal text: for 
the adult group cited in Table 42, r = 0.79, P. E. about .09. 

This relation appears, to the author at least, unexpected, and hence of 
special interest. Adults who try the test are almost unanimous in their 
declaration that their speed in reading forward is not conditioned by the 
task of assimilating the substance of the text, but solely by the physiological 
limit to intelligible articulation: their speed in reading the reversed text, 
however, is quite obviously not conditioned by speed of articulation, but by 
a sort of 'linguistic readiness,' or ease of apperceiving the constituent words 
or phrases of the text. If these statements are correct, we are evidently 
driven to the conclusion that persons wiio read difficult and complicated sub- 
ject-matter rapidly also tend to speak more rapidly — a conclusion that 
subsidiary tests appear to confirm. It is, furthermore, not unlikely that fast 
readers are also fast thinkers as well as fast speakers, though this generaliza- 
tion has at present no experimental verification. 

Notes. — We have not had sufhcient experience as yet with the 
complicated, or reversed prose test to understand fully the nature 
of the processes upon which it depends. The considerations just 
developed make it evident that these processes embrace something 
besides attention, if, indeed, attention plays any large share in the 
conditioning factors. For fast readers, in the reversed text, the 
proper combinations 'rise up' like the hidden faces in the puzjile 
picture when once they have been seen. 

Since a facile apperception of printed syml)ols Avould appear, on 
theoretical grounds, to be a natural concomitant of good intelli- 
gence, it is possible that this test may prov(^ to have considerable 



TEST 29: SIMULTANEOUS ADDING 277 

diagnostic value. To determine this point, however, it needs ex- 
tended trial with control both by introspective analysis and by the 
statistical examination of all possible functional correlations. 

REFERENCE 

Stella E. Sharp, Individual psychology: a study in psychological method, 
in A. J. P., 10: 1899,329-391. 

TEST 29 

Simultaneous adding. — In Tests 24 and 25, the attempt was made 
to measure the field of consciousness or range of attention during a 
relatively brief period. Tests have been proposed in which atten- 
tion is solicited by several claimants, not for a brief period, but con- 
tinuously. These tests may be grouped as tests of simultaneous 
activity. Their primary purpose is to ascertain how successfully 
a number of activities can be carried on at the same time. Ordi- 
narily, disparate activities are selected (Test 30) . Less often, as in 
the present case, a single type of activity is comphcated or 'spread' 
in such a manner as to demand simultaneous attention to more 
than one phase of activity. 

In simultaneous adding, as devised and conducted by Binet in 
his comparative study of six bright and six dull children, the task is 
to carry on a series of additions in three columns of figures at once. 

Materials. — Prepared forms, ruled in series of three vertical 
columns, with the numbers 6, 28, 43, printed at the head of the first 
three columns. Stop-watch. Pencil. A piece of cardboard about 
20 cm. square. 

Method. — Instruct S that he is to continue for six minutes, as 
fast as he can, adding 07ie to each number, and writing the sum 
directly below. Thus, he first writes: 7, 29, 44, then 8, 30, 45, etc. 
Exhibit a sample form on which such additions have been made. 
The moment that *S has written a line (three sums), cover it with 
the cardboard, so that he must hold the three sums in his mind from 
one line to the next. 

Record the number of additions made in 6 min., and note the 
number and nature of the errors. 

Variations of Method. — For mature *S's, the addition of 1 to 
each sum may not be difficult enough : E may then complicate the 



278 ATTENTION AND PERCEPTION 

task by requiring *S to ada, say, 3 to tlie first, 1 to the second, and 2 
to the third column. If desired, repeat the test with another vari- 
ation in the constants to be added, say, 2 to the first, 3 to the 
second, and 1 to the third column. 

Results. — (1) Binet found that this test excited a great deal of 
interest, and exacted a greater effort of attention than any he tried. ^ 

(2) There are marked differences in the amount of work (number 
of additions) done by different >S's, e.g., in Binet's tests, from 4*0 to 
96 numbers, i.e., from 13 to 32 lines of 3 numbers each. 

(3) Examination of the errors shows that *S's commonly center 
their attention upon either one or two columns : here they make few 
or no errors, but the neglected columns contain many errors. In 
other words, errors in all three columns at once are rare. Binet's 
pupils wrote 100 of 245 fines erroneously; of these 100 errors, 59 
were found in one column only, 34 in two columns, and 7 in all 
three columns. Errors are more frequent in the third column 
than the second, and in the second than the first; by count, 76, 60, 
and 31, respectively. 

(4) Contrary to the results of man} laboratory tests, says Binet, 
the number of errors committed tends to increase with continued 
work. This, we may surmise, is due in part to the fact that the 
later portion of the work necessarily deals with higher numbers, 
and in part to the confusion and loss of confidence that is fe't 
after a number of errors have been made. 

(5) Degree of intelligence appears to have little influence upon 
this test. Binet states that speed is not at all a matter of intelli- 
gence, merely an individual variation. The unintelligent make 
more errors than the intelligent, but the difference (17 vs. 13.4) 
is not as great as one might expect. 

Notes. — As a matter of fact, it is improbable that simultaneous 
adding really exacts a 'spread' of attention to all three columns. 
What *S does is to write a given line on the basis of his memory of 
the preceding line: his additions are made successively; he is not 
really adding three columns at once. The test, therefore, really 
measures what is termed "immediate memory" rather than the 



^ For detailed illustialive work secured from his .S's, consult his article, 
p. 384. 



TEST 30: SIMULTANEOUS DISPARATE ACTIVITIES 279 

spread of attention. The results may also be conditioned by the 
readiness with which S handles numbers and performs additions 
generally. 

REFERENCE ' 

A. Binet, Attention et adaptation, in A. P., 6: 1899 (1900), 248-404. 
TEST 30 

Simultaneous disparate activities. — In tachisto^j^opy and visual 
apprehension (Tests 24 and 25), we measure the rafige of attention 
for simultaneous impressions: in simultaneous adding (Test 20), 
we test the capacity of attention for concurrent activities of a 
homogeneous type: in the present test we employ disparate activi- 
ties, and study what Meumann terms " heterosensory " distribu- 
tion of attention (7, i., p. 503). Theoretically, the measure of the 
capacity of an individual to direct his attention to the execution of 
several activities at once should be of importance, since this capacity 
seems to imply the possession of such traits as keen concentration, 
mental alertness, quick-wittedness, and general ia+ .jigence. Gifted 
men, like Napoleon and Caesar, are said to have possessed this 
capacity in high degree. The latter, for instance, could dictate four 
letters while writing a fifth. 

There seems to be a possibility that such a distribution of atten- 
tion may take place und^^i some circumstances, at least a distribu- 
tion to two Mnes of activity, but strict experimental examination 
of the phc" Sli'ienon is not easy, because, in practise, one of two 
things usually occurs; if both activities are difficult, attention 
alternates between them, and the activity not attended to at any 
moment is temporarily reduced, if not altogether suspended; and 
if one activity is relatively easy, it becomes, after short practise, 
reduced to automatism, so that attention can be given freely to the 
other. It is, then, difficult, if not impossible,^ so to arrange experi- 
mental conditions as to secure continuous division of attention to 
disparate activities. On the other hand, it may be said that the 
very capacity to alternate attention quickly and successfully tiom 
one activity to another, or to reduce one activity quickly to autom- 

' Cf. the remark of Titchener (11, p. 376) : "Simultaneity of two psycho- 
logically disparate 'attentions' is, in my experience, altogether imt)ossible." 



280 atI^ention and p^koki'iton' 

atism, is itself an indication of important capacities — particu- 
larly of well-trained, highly concentrated attention, quick adapta- 
bility, and general mental alertness. 

The test selected), simultaneous reading and writing, is but one 
of a large number of possible combinations, others of which are 
suggested below. This test has been proposed by Paulhan (8), by 
Binet and Henri (2, pp. 446-7), and tried in several forms by Miss 
Sharp (9) as a test of "range of attention." 

Materials. — A selected poem — preferably one which is divided 
into a number O-' stanzas of equal length — which will be of interest 
to S, but whicli is not well-known to him. Stop-watch. Pencil 
and paper. 

Method. — (1) Let S read aloud at his norynal rate a given section 
(about 8 lines) of the poem. 

(2) Let S read another section^ of the same length, and while 
reading, write the letter a as many times as possible. Continue 
thf test b}'' the use of other sections of the poem combined with the 
writing (3) of a h, (4) of ab c, and (5) of the entire alphabet. 

This last test ■=• the most satisfactory and should be the one em- 
ployed if time permits but a single trial. It is important that S 
should try to maintain his reading at the normal rate. 

Variations of Method. — (I) Let S read both passages at his 
maximal instead of at his normal rate. 

(2) Repeat the test several times with fresh texts to determine 
the effect of practise upon its performance. 

(3) Compare the effect of striving especially for a larg? number 
of letters written with the effect of striving especially for a normal 
or for a maximal rate of reading. 

Treatment of Results. — In practise, it vnW rarely be found that 
*S maintains his normal rate of reading, particularly when writing 
the whole alphabet. To avoid the difficulty of working with two 
quantities, fate of reading and number of letters written, it is 
desirable to reduce these to a single "index of simultaneity." This 
is done, as is illustrated for the whole alphabet test in Table 43, 
by subtracting the normal reading-time from the reading-time dur- 
ing sinmltaneous activity, and dividing the number of letters 

1 Sharp ''.sed prose, and had her S's read the same section five times. 
This has t'.e disadvantage of tending to automatic reading. The advantage 
of securing identical length is practically assured here by the uses of stanzas 
of poetry. 



TEST 30: SIMULTANEOUS DISPARATE ACTIVITIES 



28] 



written by this difference.^ Thus, observer B read normally in 
28 sec, with alphabet-writing in 113 sec. — a difference of 85 sec. 
He wrote 91 letters, and has an index of 1.07. 

Results. — The results for Miss Sharp's seven S's are summarized 
in Table 43. It will be noted, (1) that the reading-time is usually 
lengthened by the complication of writing, (2) that more letters 
can be written with three than with two letters and more with two 
letters than with one letter, but not fully three times and two times 
as many, (3) that the writing of the whole alphabet is much dif- 
ferent; either the reading is very much slowed, or fewer letters are 



TABLE 43 
Simultaneous Reading and Writing. 



(Sharp) 



INDEX OP 



S's 




















REDUC 

IN 5 

READ 






1st 


2d 


■id 


4th 


5th 


o 


o6 


.. 


Alphabet 


TANEITY 

5th test 


B 


28 


38 


42 


50 


113 


47 


62 


78 


91 


85 


1.07 


G 


22 


22 


22 


21 


28 


29 


34 


39 


40 


6 


6.66 


V.M.. 


29 


30 


30 


30 


50 


40 


56 


57 


46 


21 


2.19 


W.M.. 


26 


27 


27 


27 


29 


27 


28 


36 


13 


3 


4.33 


E.R. . 


27 


27 


29 


27 


31 


31 


40 


48 


20 


4 


5.00 


L.R... 


22 


25 


26 


25 


37 


41 


44 


51 


26 


15 


1.76 


T 


27 


29 


30 


31 


29 


36 


40 


45 


25 


2 


12.50 


Aver- 
























age.. 


26 


28 


29 


30 


45 


36 


43 


51 


37 


19 


4.78 



written than when only a is employed, (4) that the S's differ mark- 
edly in their capacity to carry on two processes simultaneously. 
The rank of the S's in this test did not, however, correlate with 
their rank in any other of Miss Sharp's tests. 

(5) Paulhan noted that the simultaneous performance of two 
relatively easy activities did not take as long as the performance of 
the two in succession. He says; "I write the first four verses of 
Athalie, whilst reciting eleven of Musset. The whole performance 
occupies 40 sec. But reciting alone takes 22 and writing alone 31, 



1 Miss Sharp divided the difference by the number of letters. The reverse 
procedure has the advantage of indicating the degree of simultaneity directly, 
as a large quotient means good ability. 



282 ATTENTION AND PERCEPTION 

or 53 altogether, so that there is a difference in favor of the simul- 
taneous operations.^" And again : "I multiply 421,312,212 by 2 ; 
the operation takes 6 sec; the recitation of 4 verses also takes 6 
sec. But the two operations done at once only take 6 sec, so that 
there is no loss of time from combining them." 

Notes. — Several other tests of a similar nature may be briefly 
described; still others may be contrived by E to suit conditions. 

(1) As suggested by Meumann (p. 504), the Cancellation Test 
(No. 26) may be combined with other forms of activity, e.g., let 
S cancel one or more letters and at the same time repeat short sen- 
tences read to him by E, or listen to the reading of a page of narra- 
tion (Cf. Test 39) and repeat as much as possible of it after the 
cancellation is finished, or discriminate two "points on the skin 
(Test 23), etc. 

Vogt (12) combined the cancellation of three letters in a non- 
sense text with reaction to metronome-heats in the following manner : 
the metronome was set at 38, and the bell attachment set for every 
other stroke, so that there were 19 bell-strokes per minute; in some 
series S was required to make a slight movement of the finger at 
every bell-stroke, in other series also to lift two fingers at every 
fourth bell-stroke. Vogt found that this 'metronome-counting' 
retarded the total process of cancellation from 11.6 per cent, to 
35.2 per cent., but that it did not affect appreciably the simple 
apprehension of the letters without actual cancellation (see Test 
26, Result 11) ; in other words, he concludes that the movements of 
reaction to the metronome interfered with the movements of 
reaction in cancelling, but did not interfere with the apprehension of 
the letters in cancelling'. This result is difficult to interpret if we do 
not admit Vogt's contention that the marking is in itself an appre- 
ciable factor in the cancellation test. 

(2) McDougall (6) has proposed a form of 'dot tapping' to test 
the capacity for continuous exertion of attention in the following 
manner: Place upon a kymograph drum a sheet of white paper 
on which have been printed eight rows of 120 red dots; each dot is 
1.5 mm. in diameter, and 5 mm. distant vertically from the next 
in the row; each series of 120 dots is arranged in an irregular line 

' The 'telescoping' may amount to more than this in the case of some in- 
dividuals: soe Titchenor, 11, p. 375. 



TEST 30: SIMULTANEOUS DISPARATE ACTIVITIES 283 

which covers an extreme width of 10 mm., but the displacement of 
adjacent dots is not more than 5 mm. in the horizontal direction. 
This zigzag line of dots is now viewed, as the drum revolves, 
through a horizontal slit 10-15 mm. in the vertical dimension, 
and somewhat wider than the row of dots. S tries to strike each 
dot with a blunt soft pencil, and the drum is rotated at a speed 
(about one rev. in 23 sec.) such that he can succeed in striking 
each dot only by maximal effort. S's work is graded as follows: 
for the omission of a dot or the making of an extra mark, count 
1 error; for each lateral deviation of more than 1 mm., or each 
vertical deviation of more than 2 mm., count 1/2 error. Sample 
records show 50 to 150 errors in a series of eight rows, i.e., 960 
dots. For simultaneous activity tests, require S to undertake 
some other work at the same time, e.g., mental arithmetic, re- 
action-time with the left hand, esthesiometry, etc. 

In the few trials that the author has given this test, there has 
appeared a decided tendency for the dot-marking to lapse into 
automatism. 1 

(3) Both Binet (1) and Jastrow (5) have tested the interference 
of intellectual processes with simple motor activities.^ To repeat these 
experiments, close one end of a relatively soft-walled rubber tube; 
connect the other to a Marey tambour (Fig. 17) and adjust the 
tambour for a graphic record upon the kymograph. Let S press 
or pinch the tube either (a) at an optimal rate, (6) at a maximal rate, 
(c) in groups of 2, 3, 4, or more pressures- with stated time-inter- 
vals between the groups, e.g., 3 quick pressures per sec, (d) in alter- 
nate groups of fours and sixes, etc., (e) in time to the beat of a met- 
ronome, or (/) in time to a melody which he himself hums, or in 

^ For a modification and development of McDougall's method with par- 
ticular reference to the determination of degrees of clearness in attention, 
see Geissler (4, pp. 515 ff.). 

- Burnett (3) has recently suggested a test in which visual attention is 
measured under conditions of visual distraction. Two mazes are employed, 
which are alike in every respect save one. Each maze is an ink line drawn 
in an irregular, wandering way over a white paper surface about 18 x 26 
cm. In the second maze, small, embossed pictures and bits of paper of 
various forms and colors are scattered thickly among the twistings of the 
maze, though not actually covering any part of it. In use, the maze is 
covered with a glass plate, S is instructed to trace the pattern of the maze 
accurately and as rapidly as possible with a small wooden pointer. The 
measure of attention is afforded by the comparison of the time taken in 
Maze 1 (without distraction) with that taken in Maze 2 (with distraction). 



284 ATTENTION AND PERCEPTION 

any manner that will provide a suitably complex task'^ Mean- 
while, let him read sentences or disconnected words either silently 
or aloud, or let him undertake the mental addition of two-place 
numbers.^ 

The general results of such tests are: (1) the amount of inter- 
ference of the two activities is proportional to their complexity and 
general difficulty; (2) movements that involve counting are more 
disturbed by adding than by reading; (3) reading or adding aloud 
interferes more with motor activity than does reading or adding 
silently; (4) the reading of disconnected words is more easily inter- 
fered with than the reading of sentences; (5) additions are slower 
and less accurate when performed with, than when performed 
without, motor activity of the 'tapping' variety; (6) concurrent 
intellectual processes affect the motor activities mentioned by (a) 
lengthening the interval between pressures, (6) diminishing their 
recorded height, (c) confusing their number or arrangement, or 
{(l) causing the appearance of various motor incoordinations, 
trembhngs, unevennesses, etc., which may amount well-nigh to a 
'motor delirium;' (7) >S may or may not be conscious of these dis- 
turbances in his motor activity; in general, he can give but obscure 
or fleeting attention to the pressures if the mental task is at all 
difficult; (8) the experiment soon induces symptoms of fatigue; (9) 
incUvidual S's fer noticeably in the degree of complexity of the 
motor acti"^n * aat they can execute successfully while engaged in 
intellectual activity — differences which appear to depend pri- 
marily upon the extent to which the motor activity may be reduced 
to automatism. 

(4) Binet suggests a number of methods for testing ability to 
execute concurrent motor activities, which may, with a little ingenu- 
ity, be turned to account in the arrangement of simple tests; e.g. 
(1) make with the right hand a circular movement parallel to the 
median plane of the body in a clock-wise direction and with the left 

' One might, for instance, adopt the plan suggested by Squire (10) for meas- 
uring fatigue of attention. Use the tube and tambour; let *S memorize a ser- 
ies of eight or ten digits, e.g., 6,9,2,1,3,6,4,7, and then tap this 'pattern' as 
rapidly as possible. Introduce concurrent processes and study their effect 
upon the tapping. 

^ An excellent method is to give S two numbers to start with, and instruct 
him thereafter to add at each addition the larger digit in the previous sum, 
e.g., if 16 and 8 are assigned, the correct series will be — 16,24,28,36,42,46; etc. 



TEST 30: SIMULTANEOUS DISPARATE ACTIVITIES 285 

hand a simultaneous movement in a parallel plane in the reverse 
direction; (2) duplicate the registering apparatus above described, 
so as to provide a tube for each hand, and require S to press regu- 
larly and rapidly with the right hand, but to press with the left 
hand only twice for each five pressures of the right hand: (3) take 
a fountain-pen or pencil in each hand; with the right hand write 
some familiar poem and simultaneously with the left hand describe 
a series of small circles, or make a series of u's with the right, and a 
series of dashes with the left hand. In the last named test there 
will be seen, as a rule, a tendency toward the production of similar 
movements, i.e., the dashes become w-like, orthew's spread out in a 
dash-like fashion. If S's attention be called to this tendency, he 
may inhibit it by active control, but the tendency will usually recur 
the moment his attention becomes distracted — an observation that 
suggests the possibility of securing in this manner an index or meas- 
ure of active attention. 

REFERENCES 

(1) A. Binet, La concurrence des otats psychologiques, in Revue philos., 
29: 1890, 1.38-155. 

(2) A. Binet and V. Henri, La psychologie individuelle, in A. P., 2: 1895 
(1896), 411-465. 

(3) C. T. Burnett, A new te.st for attention against '^'straction, in P. B., 
7: February, 1910, 64. 

(4) L. R. Geissler, The measurement of attention, in . .najP., 20: 1909, 
473-529. '' 

(5) J. Jastrow, The interference of mental processes, — a preliminary sur- 
vey, in A. J. P., 4: 1891, 219-223. 

(6) W. McDougall, On a new method for the study of concurrent mental 
operations and of mental fatigue, in B. J. P., 1 : 1904-5, 435-445. 

(7) E. Meumann, Vorlesungen zur Einflihrung in die experimentelle 
Padagogilc u. ihre psychol. Grundlagen, Leipzig, 1907. (2 vols.) 

(8) F. Paulhan, La simultaneite des actes psychiques, in La Revue 
Scient., 39: 1887, 684-9. 

(9) Stella Sharp, Individual psychology : a study in psychological method, 
in A. J. P., 10: 1899, 329-391. 

(10) Carrie R. Squire, Fatigue': suggestions for a new method of investi- 
gation, in P. R., 10: 1903, 248-267. 

(11) E. B. Titchener, Lectures on the elementary psychology of feeling 
and attention, N. Y., 1908. Pp. 391. 

(12) R. Vogt, Ueber Ablenkbarkeit u. Gewohnungsfahigkeit, in P. A., 3: 
1901, 62-201. 



CHAPTER VIII 

Tests of Description and Report 

The two tests which are described in this chapter have certain 
features in common which demarcate them, on the one hand 
from the tests of perception and attention of the previous chapter, 
and on the other hand from the memory tests of the succeeding 
chapter, though, in many other respects, they resemble these tests. 

The essential idea in both of the present tests is to determine 
capacity, not merely to attend and observe, or to recall what has 
been observed, but to put the results of this observation into 
linguistic form. If the observer gives his account of the experience 
at the time of his observation, this constitutes description ; if at 
some time subsequent to his observation, this constitutes report. 

It is evident that this giving of an account of an experience, par- 
ticularly if the experience be somewhat complicated in form, is 
a more complex psychical process than those under discussion in the 
tests of attention and perception. This greater complexity makes 
the reduction of the observer's performance to exact quantitative 
terms a matter of greater difficulty, but, on the other hand, the 
activity called forth is more akin to that demanded in everyday life, 
and it is for this reason that these tests have been felt to possess a 
pecuhar value, particularly in the study of individual differences in 
mental constitution and mental efficiency. Again, language occu- 
pies so strikingly prominent a place in our mental economy that 
tests which seek to bring out the observer's ability to cast expe- 
rience into linguistic form are, on that account, well worth while. 
This is particularly the case in the second form of test, that of the 
report, which, in connection with the "psychology of testi- 
mony," has of late had a prominent place in psychological research. 

TEST 31 

Description of an object. — The description test first came into 
prominence througli the work of Binet, who lu'ged that the study 



TEST 31: DESCRIPTION 287 

of individual psychology may be best advanced by resort to the 
experimental examination of complex, rather than of simple mental 
processes, and who considered the description test of special vahie 
in this connection. Binet made preliminary tests with Henri in 
1893 (3), and worked at the test later by himself (1,2). His method 
has been followed, though not in exact detail, by LeClere (5), 
Sharp (7), and Monroe (6). 

Materials^ — Ordinary cigarette of the "Sweet Caporal" type. 
Cancelled 2-cent postage stamp.- Lithograph, entitled "Hin- 
doos."» 

Method. — (1) For the picture-test, supply S with writing mate- 
rials; place the lithograph upright before him, about 75 cm. distant. 
Instruct him: "Write a description of this picture so that one who 
had never seen it would know all about it." Allow 10 min. 

(2) For the cigarette-test, give the following instructions, and 
no others: "I'm going to put on this table before you a small ob- 
ject. I shall leave it there under your eyes. I want you to write a 
description of it; not to draw it, but describe it in words. You will 
have about 5 min. Here is the object." If S is busy at the end of 
the allotted time, or has written l)ut a few lines, the time may be 
slightly extended. 

(3) For the stamp-test, proceed in a similar manner, save that 
S's are not forbidden to draw the stamp, if they wish to. The in- 



1 The cancelled stamp was used by Monroe, the cigarette by Binet. The 
lithof?raph is substituted for the different pictures that have been used by 
other investigators (Binet and Henri used Neuville's "The Last Cartridge," 
Binet a picture representing Fontaine's "Le Laboreur et ses Enfants," 
JNIiss Sharp "The Golden Wedding" and "The Interrupted Duel"), because 
of the impossibility of securing these particular pictures, or of the difficult}' 
of using them under the conditions that prevailed in the original experiments 
(Binet's school children were well acquainted with the fable fi"om Fontaine, 
for example). 

If it is desired to extend the list of materials, E may employ other objects 
used by Binet (2), such as a box of matches, a penny, a leaf, etc. 

P'or group tests, there should be at least one picture for every 5 S's, one 
cigarette for every 2 S's, and a stamp for each S. 

2 For group tests, it would be desirable to secure a set of stamps whose 
cancellation marks were approximately the same. The stamps should be 
trimmed off in such a manner as to show the full border of the stamp and a 
narrow margin of the paper upon which it was attached. 

^ This picture is one of a scries called Leutemann's Types of Nations, 
catalogued by E. Steiger & Co., New York. It may be purchased, like all 
other materials cited in this book, of C. H. Stoelting Co., Chicago, 111. 



288 DESCRIPTION AND REPORT 

structions may run: "Describe this postage stamp so that a per-' 
son who had never seen one would know all about it." Allow 10 
min., or more if needed. 

Treatment of Data. — In general, the results of the description 
test are not intended to be submitted to exact quantitative treat- 
ment, but are to be inspected for the purpose of forming an opinion 
of S's general mental type and capacity. The papers may, how- 
ever, be treated quantitatively, by (1) counting the number of 
words written, or (2) counting the number of lines written. E may, 
further (3), record in general terms the readiness and ease with 
which S undertakes the description, and (4) may rate his paper as 
a whole, with respect to its comparative merit, on a score of 10 for 
a satisfactory or adequate description. (5) The description may, 
perhaps, be classified also with respect to its general type or char- 
acter, following the classification adopted by Binet, Le Clere, and 
others as explained below. (6) Descriptions of the postage stamp 
may also be catalogued with respect to the items mentioned, 
as was done by Monroe. 

Results. — (1) The description of an object is inadequate, be- 
cause it is almost invariably simplified, i.e., a considerable number 
of its features, even important features, are unmentioned. Thus, 
in one of Binet's photographs, of the 22 objects or features that 
were mentioned at all, only 9.4 were mentioned, on the average, in 
each description. 

(2) This simplification or reduction in the description is the 
result of what might be termed a process of selection. Certain 
features are mentioned in practically all descriptions, others are 
mentioned only occasionally. By tabulating the number of times 
each feature is mentioned, one may discover some of the principles 
which condition this selective process. Thus, in Binet's picture of 
the "Laborer," the old man is mentioned 36 times, his sons 30, 
his bed 29, the seated woman 27, etc., until we come to relativelj^ 
unimportant objects that ma}^ almost escape mention at all, e.g., a 
stick in the hands of one of the children — only 4 times in 36 
descriptions. When pictures are used, persons are more often 
mentioned than furniture or other details of the setting of the 
scene. 

Similarly, in the stani]:) test, tabulation indicates, according to 



TEST 31 : DESCRIPTION 289 

Monroe, the following order of frequency of mention: (1) word- 
inscriptions, (2) color, (3) number-inscriptions, (4) portrait, (5) 
substance, (6) form, (7) use, (8) perforated edge, (9) size, (10) can- 
cellation, (11) ornamentations. The item use declines with age: 
all others are mentioned more frequently as age increases. 

(3) Sex differences. Monroe states that girls generally mention 
more items than boys, and "seern to surpass boys in their knowl- 
edge of the postage stamp." It is not clear, however, whether this 
seeming superiority is due to better observation, to greater industry, 
or to greater zeal and conscientiousness. 

(4) Individual differences. In 150 accounts of the photograph, 
Binet found no two alike. This wealth of individuality makes the 
description-test at once valuable and difficult — valuable as an 
indication of the variety of mental constitution, difficult as to 
quantitative or comparative treatment. As an extreme illustra- 
tion, one may contrast the following descriptions of a postage- 
stamp — the first by a girl of 8, the second by a boy of 16. 

(a) "The postage stamp has a picture in it. The postage stamp costs 
two cents. It says united states postage on it. The man has hair braided 
in back of his head. The Boarder is round. It has arms on it. The shape 
is square. The color is red. The man is White. You can get these to the 
postice [post-office] for two cents. There are lines around the boarder. 
The back of the stamp is white. It has nomber 2 on each side of it. The 
man has longhair." 

(b) "comments on the accompanying TJ. S. of AMERICA 2 CENT POSTAGE 
STAMP. 

"1. Its meaning: The Postage stamps have glorious history. In the 
past 57 years they have been more and more useful until now they are not 
only absolutely necessary, but constitute one of the great helps in the study 
of Geography, and one of the noblest pleasures for thousands and millions of 
people; Kings and Queens as well as children in the most miserable social 
condition. 

"2. This Postage Stamp has the red color and is now next to the one penny 
^^tamps of Great Britain the most extensively used stamp used in the world. 
If I am not wrong its circulation in the past and present is the next largest of 
all others. The one penny stamp, I think has the first place. 

"3. Its surroundings are very interesting. It is mounted on a piece of 
]iaper, remainder of an envelope, which fact easily indicates that it is used 

in the most cases for letter correspondence. I notice [Continues in 

tiiis and the next paragraph a description of the stamp itself.] 



290 DESCRIPTION AND REPORT 

"5. Some particular observations. I had 500-600 of them at home which 
my cousin had the kindness to send me. Of course they are of no special 
value, but yet thej' teach my little brothers the important lesson that such 
a little thing, like a stamp, will do all the necessary things for the transpor- 
tation of a letter or other mail matter from the Atlantic to the Pacific. It 
is very interesting to me that with the march of civilization the great Postal 
system of the World has increased its actions more and more until it is now 
one of the chief functions under the sun. How much this single stamp has 
done I cannot say, but I know that some stamps, precisely like this, have 
done great service to the country." 

(5) Types. Notwithstanding this diversity, investigators have 
sought to classify descriptions into a hmited number of types. 
Thus, Binet proposes four tj^pes — the descriptive, the observa- 
tional, the emotional (poetic, imaginative), and the erudite — each 
present in varying shades and degrees. 

(a) The describer, or enumerator, as one might term him, merely catalogs 
the features of the object before him, with little regard for their interrela- 
tions, or for the meaning of the object as a whole. 

Example: "The cigarette has the general form of a cylinder, cut at one 
end by an inclined plane where the paper is folded. It is stuffed with a 
rather dark brown tobacco. The paper is striped lengthwise. The paper is 
somewhat bruised. The tobacco projects about 0.5 centimeter from one 
end." 

(b) The observer, though not necessarily more intelligent or clever than th e 
describer, places more emphasis upon the interrelations of the several 
features that he mentions, interprets what he sees, conjectures and indi- 
cates the significance of the object as a whole. This type is also mentioned 
by INIrs. Bryant in her ' description-of-a-room ' test (4). 

Example: "A long, white, round object, composed of a paper cylinder, 
about 1/2 or 3/4 centimeter in diameter, filled with what is probablj' Oriental 
tobacco. It is about 7 centimeters long and must weigh about 6 grams 
[really 2 g.]. It is a badly rolled, uneven cigarette, and has been handled 
since it was pasted. In two places, to the right and left of the middle, the 
paper shows streaks as if it had been twisted. Other horizontal depressions 
indicate that there has been some pressure exerted upon the cigarette. I 
don't see the line where it has been stuck, but it must be badly fastened." 

(c) The emotional, imaginative, or poetic S is less accurate in observation, 
but introduces emotion, sentiment or imaginative interpretation in his 
description. 

Example: "It is a cigarette. It is thin, long, somewhat wrinkled. Its 
shape suggests a kind of elegant ease. Is it the cigarette itself, or the mem- 
ories that it awakes that remind me somehow of a scape-grace? The cigar- 



TEST 31 : DESCRIPTION 291 

ette, there, all by itself on the table, makes me think of the bad student that 
goes off in the corner by himself to smoke. But I must write about the cigar- 
ette itself, and banish the idea of the smoker," etc' 

(d) The erudite S tells what he knows, what he has been taught, or inter- 
jects bits of personal information about the object. This may indicate the 
presence of an unusual fund of information, or it may indicate sheer laziness, 
in that it is often easier to write what one knows than actually to describe 
from direct inspection. 

Example: "We have before us here a cigarette. Let us see how it is made, 
In the first place, the exterior envelope is of light paper, called silk-paper. 
Then, inside is the tobacco. Tobacco is a product that grows almost every, 
where in warm or temperate climates. The leaves of this shrub are gathered- 
and, after a treatment which lasts four years, are turned over to the public 
in the form of powder, that is, snuff, or in shreds, as in the present instance," 
etc. 

Miss Sharp did not attempt a classification into types, but noted that S's 
observation "may be primarily directed to the particular objects or details 
of the picture, to the general arrangement of the objects, that is, the compo- 
sition of the picture, or to the meaning of the picture, the story which it con- 
veys, — the details observed being such as lead up to this interpretation, or 
explain and apply the interpretation that is given first. The different ways 
in which the same picture appeals to the various individuals indicate dif- 
ferences in mental constitution." * 

The results of LeClere's test are not directly comparable with those of 
other investigators, because his instructions were not to describe the object 
(gold watch), but to "write something that comes into mind as you look at 
it." He distinguishes in the contributions made by 30 girls, aged 13 to 17 
years, seven types, viz : description, observation, imagination, moral reflec- 
tion, erudition, pure or simple emotion, and esthetic emotion. He does not 
find, however, that any one of his 5's contributes a paper that may be classi- 
fied in any one of these types, nor does any paper give evidence of a 'com- 
plete mind,' in the sense that all seven of the types are represented therein. 
In general, older or relatively more intelligent children write more varied or 
complex papers, i.e., approach the theoretically 'complete' type of mental 
constitution. 

Notes. — The attempt to Uvse the description test for classifica- 
tion of S's into types of mental constitution is of obvious interest : 
the drawing of inferences from such a classification as to the men- 
tal make-up of the iS's is as obviously hazardous, for S may write his 
description in the vein that he thinks is wanted by E. Thus, Binet 
had reason to think that several S's that he had classed as poetic 
or emotional were actually, in their everyday life, of a very matter-- 



292 DESCRIPTION AND REPORT 

of-fact and unsympathetic disposition. In general, the drawing of 
inferences from the work of S's would become safer in proportion 
as the descriptions were increased in number and variety, i.e., an S 
who wrote in an emotional vein in four descriptions of four dif- 
ferent objects has, presumably, a real emotional constitution. 

REFERENCES 

(1) A. Binet, Psychologie individuelle. La description d'un objet, in 
A. P., 3 : [1896] (1897), 296-332. 

(2) A. Binet, L'etude experimentale de I'intelligence, Paris, 1903. Pp. 
309. 

(3) A. Binet and V. Henri, La psychologie individuelle, in A. P., 2: 1895, 
(1896), 411-465. 

(4) Sophie Bryant, Experiments in testing the character of school children, 
in J. of the Anthrop. Inst, of Great Britain and Ireland, 15: 1886, 338-349. 

(5) A. LeClere, Description d'un objet, A. P., 4: 1897 (1898), 379-389. 

(6) W. Monroe, Perception of children, in Pd. S., 11: 1904, 498-507. 

(7) Stella Sharp, Individual psychology ; a study in psychological method, 
in A. J. P., 10: 1899, 329-391. 

TEST 32 

Fidelityof report (Xassa^e test). — Capacity to observe, or range 
of observation, may be tested by methods previouslj^ described 
(Tests 25 and 31); native retentiveness or capacity for recall may 
be tested by methods such as those that are described in subsequent 
sections ; capacity to describe what is seen may be tested as has been 
indicated in Test 31, but there exists a type of activity, that of report- 
ing a previous experience, which in a way combines these several 
activities, in that it demands both attentive observation, retention, 
recall, and an ability to marshall and formulate the items of exper- 
ience in a verbal report (Aussage). In studying the 'psychology of 
testimony,' interest has been developed of late in the direct exam- 
ination by experimental methods of the capacity to report, itself, 
and it has been found that reports may exhibit varying degrees of 
fidelity or reliability, more or less independently of the capacity 
that the reporters possess to observe or to retain experience; 
in other words, discrepancies or inadequacies may appear in 
reports, which are due, not only to misdirected attention, mal- 
observation and errors of memory, but also to lack of caution or of 



TEST .S2: FIDELITY OF REPORT 293 

zeal for accurate statement, to scanty vocabulary, to injudicious 
phraseology, or, of course, to deliberate intent to mislead.^ 

Historically, the idea of subjecting capacity of report to test 
seems first to have been definitely proposed by Binet (1). Since 
then, the study of the psychology of testimony has found its most 
enthusiastic and active expositor in Stern, who has written an 
extensive monograph (15) on the subject, and in whose periodicals 
(Beitrdge zur Psychologie der Aussage and Zeits. f. angewandte 
Psychologie) most of the work of subsequent investigators has, 
directly or indirectly, appeared. The applicability of this line of 
work to many practical problems, particularly in the field of juris- 
prudence, is too obvious to need further comment. 

GENERAL METHODOLOGY OF THE REPORT-TEST 

1 . Choice of material. Of the several types of material that have 
been elaborated for the study of the report, e.g., the picture-test, 
the event-test, the rumor-test, etc., the first mentioned has many 
advantages for our present purposes.^ Two types of picture-test 
are prescribed; the first closely patterned after that employed by 
Binet in his study of suggestibility in school children, the second 
more in accord with the stock picture-test, as developed by Stern, 
Borst, Wreschner, Lobsien, and others. 

2. Choice of exposure-time. For pictures, times ranging from 
5 sec. to 7 min. have been used, though 45-60 sec. is most usual. 

1 It is true that no hard and fast line can be drawn between the report-test 
and the test of range of apprehension, or between it and the ordinary mem- 
ory-test; in the main, however, range of apprehension implies a brief expos- 
ure followed by simple enumeration of the objects seen, so that what is 
tested is capacity to grasp or observe, rather than capacity to retain or to 
formulate. And the stock memory-test measures the amount of material 
that can be reproduced; here the learning is usually by heart, and the repro- 
duction is largely mechanical. In the report-test, the object is more com- 
plex, the time of scrutiny much longer than in the observation-test, while 
stress is placed as much upon quality as upon quantity of reproduction, 
especially upon the fidelity of reproduction as conditioned by such personal 
factors as timidity, cautiousness, assurance, skill in verbal formulation, etc. 
Nevertheless, in the interrogatory, the report-test does closely resemble an 
ordinary test of memory. 

^ For a discussion of these advantages, of the several methods in detail, 
of the chief results, and for a general review of the whole field of the psy- 
chology of testimony, the reader is referred to an earlier discussion by the 
author (17). Suggestions for further tests will likewise be found therein. 



294 DESCRIPTION AND REPORT 

The principle whicli has controlled the choice of exposure-time for 
the two tests that follow is to select such a period as will permit an 
average S to examine each detail of the object once. 

3. Choice of time-interval. For the sake of brevity, the instruc- 
tions that follow prescribe a report directly after the exposure. If 
circumstances permit, E will find it of interest to extend the inter- 
val ^-o several minutes, or even hours or weeks. The effect of length- 
ening time-interval has not as yet been satisfactorily determined. 

4. Choice of form of report. There are two distinct forms of re- 
port, (1) the 'narrative' {Bericht, recit), (2) the 'interrogatory' 
{Verhor of Stern, Prilfung of Wreschner, interrogatoire of Borst, 
forage de memoir e or questionnaire of Binet).^ The narrative is a 
free account, delivered by S, either orally or in writing, without 
comment, question, or suggestion by E\ the interrogatory is a 
series of prearranged questions; the replies to these questions con- 
stitute the 'deposition' (Verhorsprodukt). The constituent parts 
of the narrative or the deposition may be termed 'statements' 
or 'items.' Each form of report has its advantages and its dis- 
advantages : both should be employed whenever possible. 

5. Choice of form of interrogatory. An interrogatory is ' complete ' 
when its questions cover all features of the experience exhaustively, 
and are propounded to all S's in the same order and manner : an 
interrogatory is ' incomplete ' when its questions are restricted to 
such as refer only to those items not mentioned by S in his nar- 
rative. The interrogatories that follow are designed to be com- 
plete, but E may, by appropriate selection, convert them into 
the incomplete type. 

6. Choice of questions. The form of questioning very materially 
affects aS's deposition, particularly if the questions are of the type 
known as ' leading ' or ' suggestive ' questions. If we follow Stern, at 
least six types of questions may be framed, viz: determinative, 
completely disjunctive, incompletely disjunctive, expectative, and 
consecutive. 

^ The terminology of the report-experiment has developed in Germany 
and France. I have been obliged to coin English equivalents — a task not 
always easy because the foreign terms have not been chosen with special 
care to secure consistency or to accord with legal phraseology. For this 
reason, the foreign equivalents are included here, and elsewhere in the 
discussion. 



TEST 32: FIDELITY OP REPORT 295 

A completely disjunctive question is one that forces the reporter to choose 
between two specified alternatives, e.g., "Is there a dog in the picture?'' 

An incompletely disjunctive question is one that offers the reporter a choice 
between two alternatives, but does not entirely preclude a third possibility, 
e. g. " Is the dog white or black? " In practise, for many reporters, especially 
for children, this form is virtually completely disjunctive, since a certain 
amount of independence is demanded for the choice of the third possibility, 
e.g., for the answer "The dog is brown." 

An expectative question is one that arouses a moderately strong suggestion 
of the answer, e. g., "Was there not a dog in the picture? " (This is the form 
used by Binet to induce moderate suggestion.) 

An implicative question is one that assumes or at least implies the presence 
of a feature that was not really present in the experience, c. g., "What color 
is the cat?" In practise, it is clear that a determinative question might 
become implicative if the reporter had completely forgotten the item to 
which it referred. (The implicative question was used by Binet to induce 
strong suggestion.) 

The consecutive question is any form of question that is used to augment a 
suggestion that has been developed by previous questions. 

7. Choice of method of grading. Treatment of data. In general, 
the adequacy of a report depends both upon its quantity and its 
quality: quantity is measured by the number of items mentioned 
or the number of questions answered (in absolute or in relative 
terms) and is referred to as the range of report {Umfang, etendue) : 
quaUty is measured by the fidelity of the statements made, and is 
referred to as the accuracy of report {Treue, fidelite). 

We have also at our command useful indications of the positive- 
ness or degree of assurance that S places in his report. Besides (1) 
complete uncertainty (''I don't know" or "I have forgotten"), we 
may distinguish (2) hesitancy ("I think" or ''I believe"); (3) posi- 
tive statement or assurance of ordinary degree, and (4) attestation 
or attestable assurance, i. e., the highest degree of assurance, as 
indicated by *S's willingness to take his oath that the statement is 
correct. 

On this basis, the data may be subjected to treatment for the 
computation of a number of 'coefficients of report,' by the aid of 
the following simple formulas: 



296 description and report 

Coefficients of Report.^ 

Let P = number of possible items, 

/i = number of items reported (or replies made), 
f = number^ of items reported with certainty (in- 
cluding attestation) , 
a = number of items whose correctness is attested 
under oath, 
n{N) = number of items reported in the narrative, 
niP) = number of items reported in the deposition, 
n{r) = number of items that are rightly reported, 
c{r) = number of items that are certain and right, 
a{r) = number of items that are attested and right, 
a{w) = number of items that are attested and Avrong, 
Then 

(1) n = range of report, absolute {Umfanci, etendue), 

(2) n/P = range of report, relative, 

(3) >i(N)/n(D) = spontaneity of report, 

(4) n{r)/n = range of knowledge {Umfang de.s Wissens, 

etendue du savoir) , 

(5) n{r)/c = accuracy of report (Trene, fidelite), 

(6) c/n = assurance {subjective Sicherheit, assurance), 

(7) c{r)/c = reliability of assurance (Zuverldssigkeit der 

Sicherheit, Sicherheitsherechtigiing , fidelite 
de la certitude), 

(8) c(r)/n = warranted assurance (Sicherheit der Person, 

assurance justifiee) , 

(9) c(r)/n(r) = accuracy of assurance (justesse certifiee), 

(10) a/n = tendency to oath or attestable assurance (ten- 

dance au serment) , 

(11) a(r)/n = warranted tendency to oath (tendance au ser- 

ment veridique), 



'■ The fourth formula is used by many writers, in place of the fifth, for 
accuracy of report; as here indicated, however, the indeterminate cases 
(" I don't know") are omitted from the denominator in computing accuracy. 

Next to range and accuracy, the most important coefficient is probably 
warranted assurance (8th formula), as a high ratio indicates a good witness, 
who reports a large number of items both correctly and with assurance. 



TEST 32: FIDELITY OF REPORT 297 

(12) a(w)/n = unwarranted tendency to oath (tendance au 

faux-temoignage) , 

(13) a{r)/a = reliability of oath (^deZi^e rfw sermeni), 

(14) a{w)/a =unrehal)ility of oath {infidelite du serment) . 

The determination of P, and hence of relative range of report, is often 
beset with difficulty : the most practical working rule is to rank as 'one item' 
any combination of features that forms a single natural working group, the 
details of which would escape individual observation under ordinary con- 
ditions. Or, again, P may be taken as the number of separate items men- 
tioned by a competent S in describing the picture or test-object by direct 
observation. 

Although different errors unquestionably have different degrees of impor- 
tance (to forget a man is more serious than to forget the color of his necktie), 
no satisfactory plan for arbitrarily 'weighting' different items has been 
devised. 

The psychologically best method of grading is unquestionably to classify 
the data statistically according to various categories — such as persons, 
objects, colors, sizes, etc. — and to compute range, accuracy, assurance and 
the other coefficients for each category separately. This will greatly in- 
crease the labor of quantitative treatment, but it will afford valuable insight 
into the qualitative conditions of report that could not otherwise be secured : 
the several coefficients can, for comparative purposes, be united subse- 
quently into a single series of coefficients for the person or persons under 
consideration. 



A. REPORT-TEST WITH BINET S CARD OF OBJECTS 

Material. — ^Rectangular sheet of orange-yellow cardboard, 
33.5 X 40.5 cm., to which are attached two photographs, a label, 
a button, a penny, and a postage stamp.^ Watch. 

Method. — Give >S' the following instructions: "I want to try an 
experiment with you to see how good your memory is. I am going 
to show you a large card with a number of things fastened on it. 
You will have just half a minute to look at it. Half a minute is 
a pretty short time, so you must look very carefully, because 
afterwards I shall want you to tell me what you have seen, and I 
shall ask you questions about many little details, and I want you 



' These objects are not exact duplicates of theBinet group, and the card is 
somewhat larger. The exposure-time and the questions of the interrogatory 
have been correspondingly modified. 



298 DESCRIPTION AND REPORT 

to answer these questions exactly, if you can. Do you under- 
stand"? 

Place the card directly before ti in a good light. At the -end of 
30 sec, remove it and keep it well concealed. Direct *S at once : 
"Now tell me everything you saw: describe it so clearly that if I 
had never seen the card I should know all about what was on it." 
The narrative is given orally by S, and recorded verbatim by E, 
without comment, query, or suggestion. Reread the report to ;S, 
and ask him to indicate what statements he is so sure of that he 
would swear to their accuracy. Underline these statements. 

Proceed next with the interrogatory. If joossible, ask S the fol- 
lowing questions in the order given^ . Record his rephes by number, 
verbatim, and underline all attested replies. 

Interrogatory for the card of objects. 

(1) Did you notice a coinf 

(2) What kind of a coin is it? (What denomination?) 

(3) Does it show 'heads' or 'tails'? 

(4) Is it bright or dull? 

(5) Is it in good condition, or scratched and marred? 

(6) Did you notice a button? 

(7) What is its shape.? 

(8) What is its color? 

(9) Is it the same color all over? 

(10) Is it made of cloth or of some other substance? 

(11) How many holes are there in it? 

(12) How is it fastened to the cardboard?^ 

(13) Did you notice a small picture near the top of the cardboard? 

(14) What color is it? 

(15) What shape is it? 

(16) What does it represent? 

(17) How many persons are there in it? 

(18) What is the lady doing with her right hand? 

(19) What color is her dress? 

(20) What is the other person doing? 

' S may interfere with this program, either by anticipating the answers 
to some questions, or by committing errors, e,g., describing an essentially 
different scene in the larger photograph; in such an event, E must devise 
other questions to follow up the cues thus given. 

■'If »S replies "By a thread," ask further questions, e g., "Do the threads 
pass through the holes or around the whole button?" "Draw them." 
"What color are they?" etc. 



TEST 82: FIDELITY OF REPORT 299 

(21) Where is he sitting? 

(22) What is he looking at? Describe it exactly. 

(23) Is the name of the picture printed on it? 

(24) Did you notice another picture? 

(25) What shape is it? 

(26) What color is it? 

(27) What does it represent? 

(28) How many persons are there in it? 

(29) How are they dressed? 

(30) Where are they standing? 

(31) How many animals are there in the picture? 

(32) Is the cart on wheels or not? 

(33) Are there any words printed in the picture? What are they? 

( 34) What did you see in the background? 

(35) What did you see in the foreground? 

(36) Is the picture taken in summer or winter? How do you know? 

(37) Did you notice a stowpf 

(38) Is it American or foreign? 

(39) How much is it worth? (What denomination?) 

(40) What color is it? 

(41) On what part of the cardboard is it? 

(42) Is it a new one or has it been used? (Describe the cancella- 

tion-mark.) 

(43) Did you notice a label? 

(44) What color is it? 

(45) What shape is it? (Is it perfectly rectangular? Draw it.) 

(46) Is any printing on it? What? 

(47) Is there any border around the printing? 

(48) How is it fastened to the cardboard? 

(49) How is it placed on the cardboard — right-side up, slanting, 

or how? 

(50) What color is the cardboard? 

Variations of Method. — ^(1) Mature S's may be tested in 
small groups, though this is not recommended. Both [narrative 
and deposition must then be written by the S's. For comparative 
purposes, the same procedure must be followed for all S's, since 
oral and written reports cannot be assumed to be equivalent. 

(2) To induce a moderate degree of suggestion, E may recast the 
questions of the above interrogatory into an expectative form, and 
add others, e.g., in place of No. 12: ''Is not the button fastened 
to the cardboard by a thread"? In place of No. 31: "Isn't there 
a little dog besides the horse"? In place of No. 42: "Isn't the 



800 ^ DESCRIPTION AND REPORT 

postage-stamp cancelled"? Or, for additions: "Isn't there a sev- 
enth object on the cardboard"? "Draw it." "Are there not four 
wheels on the cart"?, etc. 

(3) To induce a strong degree of suggestion, E may recast the 
(luestions given into an implicative form, and add others as desired : 
e.g., in place of No. 7: "Draw the button so as to show the place 
where it is broken." In place of 31 : "Are both horses of the same 
color"? In place of 42: "Describe the cancellation-mark on 
the stamp." In addition to 45: "What else does the label have on 
it besides 'Glass. Handle with care.' "? Or, in place of 21: "Does 
the little boy's mother put her arm around him as he sits in her 
lap"? For additional questions, devise a number such as: "Is the 
lady's necktie dark brown or blue"?, etc. 

Results. — (1) In the narrative, Binet^ found that, of 23 
children, aged 9-12 years, only four mentioned all 6 objects, 10 
mentioned 5 objects, 8 mentioned 4 objects, and 1 only 3 objects. 

(2) In order of omission (for Binet's own objects), he found the 
stamp forgotten 10 times, the tag 9, the button 4, the coin 3, the 
l)ortrait (smaller picture) 2 times, and the larger picture never. 

(3) In tests of older children with written narratives, Binet 
found little difference in the total number of objects mentioned, 
but marked differences in the wealth of details and the precision 
of their formulation. 

(4) The objects have distinct individuality, i.e., though S may 
forget the color or the value of the stamp, yet if he recalls the 
object at all, it is as a stamp, not, for instance, as "some square, 
greenish-colored thing." In other words, S recalls a thing, not a 
number of meaningless attributes.^ 

(5) S's may report very precisely and with assurance objects 
or features of objects which are totaLy incorrect, e.g., they may 
draw the thread fastening the button, and take oath as to its 
presence. Hence, testimony given with precision and detail and' 
with the highest degree of assurance may be absolutely false. 

(6) S's may recall one feature of an object exactly, but fail 

' For a detailed presentation of these results, see his book, pp. 255-329. 

^ In the author's study of range of visual apprehension, however, there 
appeared numerous cases of the character thus denied by Binet, for exam- 
ple, a nickel was recalled only as "something bright and round in the upper 
corner of the cardboard." 



TEST 32: FIDELITY OF EEPORT - 301 

entirely in their description of another feature of the same object 
e.g., recall that the label is red, but err as to its shape. It follows 
that, in te>stimony, a witness whose assertions are verified in many 
details may, nevertheless, err in his statements with regard to some 
other detail that happens not to be susceptible of verification. 

(7) If S fails to mention an object in his narrative, but recalls 
it immediately in the interrogatory, his further characterization 
of it may be quite as accurate as that of other aS's who had re- 
called it spontaneously. 

(8) In comparing different types of questions, Binet found 26 
per cent error for indifferent, 38 per cent for moderately suggest- 
ive, and 61 per cent error for strongly suggestive questions. 

B. REPORT-TEST WITH A COLORED PICTURE 

Materials. — Set of four colored pictures: "Austrahans," "A 
Disputed Case," "Washington and Sally," and "The Orphan's 
Prayer."^ Watch. 

Method.— Give S instructions analogous to those in the pre- 
ceding form of report-test, but without specifying the time of 
exposure. Expose the picture for 20 sec. Secure a^n oral narrative 
and deposition as directed above. Suggestions for interroga- 
tories for two of the pictures follow. 

Interrogatory for "A Disputed Case." 

(1) How wide is the picture (horizontally)? 

(2) How high is the picture (vertically) ? 

(3) Is there any border: if so, what color? 

(4) How many persons are there in the picture? 

Take the person on your right : 

(5) Is he young, middle-aged, or old? 

(6) What is his posture, — sitting, standing, or lying down? 



' All four pictures may be procured through C. H. Stoelting Co., Chicago, 
111. The "Australians" is a large lithograph, one of a series called Leute- 
mann's Types of Nations, catalogued by E. Steiger & Co., New York City. 
It is recommended for use with large groups, numbering from 10 to 50 or more 
.S's. The "Hindoos" lithograph prescribedin Test 31 may be used with this 
for check tests, as it is of the same dimensions and of similar character. 

The "Disputed Case" (No. 1235 of the Taber-Prang Art Co's collection) 
is recommended for use save for very young children or for large groups. 
"Washington and Sally" and "The Orphan's Prayer" (Nos. 699 and 1207. 
respectively, of the same collection) may be used for subsidiary and check 
tests. 



302 DESCRIPTION AND REPORT 

(7) What is he doing? 

(8) What is his facial expression? 

(9) Is he bald or has he abundant hair? 

(10) What color is his hair? 

(11) Is he smooth-faced or has he a moustache or a beard? 

(12) What color is his beard? 

(13) Does his moustache conceal his mouth? 

(14) Does he wear eye-glasses or spectacles? 

(15) Has he a hat on? What kind? What color? 

(16) Where is his right hand? 

(17) Where is his left hand? 

(18) What color is his coat? 

(19) W^hat color is his shirt? 

(20) Has he a collar on? 

(21) What color is his necktie? 

(22) What color is his vest? 

(23) What color are his trousers? 

(24) Does he wear slippers or shoes or boots? 

Take the person on your left : 
(25-44) Repeat questions 5-24. 



(45 
(46 
(47 
(48 
(49 
(50 
(51 
(52 
(53 
(54 
(55 
(56 
(57 
(58 
(59 
(60 
(61 
(62 
(63 
(64 
(65 
(66 
(67 
(68 



What kind of light or lamp is used? 

Where is it placed? 

Where is the ink-well? 

Is there not a pen in it? 

What color is the dog? 

Is there a table or bench? 

How long is it (really)? 

What color is the table cloth or covering? 

Is the fringe of the same or of a different color? 

Name the objects on the table. 

How many chairs are there in the room? 

Is the rocldng chair on yowc left or on your right? 

Is there an umbrella? 

Do you think it is jet-black or dark-blue? 

In what position is it? 

Name the objects in front of the table on the floor. 

Is there a satchel or dress-suit case in the room? Which"; 

Is it open or shut? 

What do the pictures on the wall represent? 

How many windows are visible? 

Can you see any detail of outdoor scenery through them? 

How many hats are there in the room? 

Describe and locate them. 

Can you recall the time indicated by the clock on the wall": 



TEST 32: FIDELITY OF REPORT 303 

(69) What object is on your extreme right? 

(70) Are there any books in this part of the room? 

(71) What color is the wall? 

(72) Where is the newspaper? 

(73) How long did you see the picture? 

Interrogatory for the '^ Australians." 

(1) How many persons are there in the picture? 

(2) How many animals? 

(3) What kind of animals? 

(4) What is the person on your left doing? 

(5) What is the object behind him? 

(6) What is the person in the center of the picture doing? 

(7) Has this person a beard or not? 

(8) Is the man who is in charge of the dog holding him by a 
leash (guiding rope) or by taking hold directly of the scruff 
of his neck? 

(9) What are the persons in the background doing? 

(10) Do the persons in the foreground wear anything beside 
the loin-cloth? 

(11) What color is their skin? 

(12) What color is the dog? 

(13) What is the most peculiar thing that you noted in the 
appearance of the men in the picture? 

(14) What objects lie in the immediate foreground? 

(15) Is there any water represented in the picture? 

(16) Is the white man standing on the left or on the right? 

(17) Is the sun represented in the picture as shining from your 
right or from your left? How do you know? 

(18) How long did you see the picture? 

Variations of Method. — Test the effect of varying the time 
of exposure, of extending the time-interval between exposure and 
report, of repeating the report (narrative or interrogatory), with- 
out further exposure, two or more times at intervals of several 
days or weeks. ^ 

Typical Results.— The following narrative by a college senior, 
a man of varied experience, mature, much travelled, and well 
trained, though of mediocre native ability, shows clearly the tend- 
ency of 'an adult S to describe a situation, a meaningful whole, 
rather than merely to enumerate details, as do many children. 
Indeed, the detail here is distinctly subordinated to the interpre- 

'- See Ref. 17 for further suggestions. 



304 DESCRIPTION AND REPORT 

tative rendering. The narrative tells what the picture is about, 
rather than what it is. 

"The picture, about 10 X 10 inches, represents a scene that would be 
typical of a rural justice of the peace and a man who has come to ask his 
advice on some subject. The Justice sits before his desk, an old manuscript 
before him, one hand on his head as if he had not yet given his decision. The 
office is filled with books and on one of them in the left of the picture rests 
his top-hat. The visitor seems to be troubled very much: his clothing 
denotes that he is of a different station in life. He has placed his carpet- 
bag on the floor and his hat near it, as a sign of great mental strain, which 
seems to increase as he awaits the decision. On the wall to the right is a 
double map of the world, showing, perliaps, that the Justice is a man of 
wisdom and a source of information to his neighboi's. The room, furniture, 
the manner of dress would have denoted a time long before ours. The men 
seem to be about 65 or 70 years of age." 

In his deposition, this student rendered an unusually full list 
of an.swers: the reply — ''I don't know" — is given only twice 
(Questions 34 and 72). The range of report is, therefore, large, 
but the fidelity is relatively small, since the following erroneous 
statements appear (those italicized are attested statements) : 

The picture is 14 X 14 inches. The man on the right is bald, wears spec- 
tacles, has his right hand on a paper, wears a collar, a purple tie, black 
trousers, and slippers. The man on the left is thinking hard, has a troubled 
expression, wears a sandy moustache: he has his right hand in his pocket, 
his left on his knee: he wears a light colored vest and brown trousers. The 
room is lighted by a candle which stands on the pile of books. There is a 
pen in the ink-well. The table is 14 feet long, has a light-colored cloth top 
with fringe of a different color. There are three chairs in the room, the rocker 
being at the left. The umbrella is dark blue in color and lies on the floor. There 
is a coat on the floor in front of the table; there is a basket on the table. The 
satchel is shut. One window is visible. There is a chair at the extreme right 
of the picture. The wall is w^hite. (The cuspidor and the newspaper are not 
recalled.) 

General Results of Tests of Report. — (1) . Accuracy. The 
chief single result of the Aussage psychology is that an errorless 
report is not the rule, but the exception, even when the report is 
made by a competent .S under favorable conditions. Thus, in 240 
reports, Miss Borst found only 2 per cent errorless narratives and 
0.5 per cent errorless depositions.^ 

' These errorless reports are commonly characterized by very small range : 
they are the reports of <S"s who are extremely cautions and state only 
what they are certain of. 



TEST 32: FIDELITY OF REPORT 



305 



The average S, when no suggestive questions are employed, 
exhibits a coefficient of accuracy of approximately 75 per cent. 

(2) Range and accuracy. There is no general relation of range to 
accuracy, though, for a given S, it is doubtless true that there 
is an inverse relation between these two coefficients.^ 

(3) Range and other constants. There is no general parallelism 
between range of report and other coefficients which depend upon 
degree of assurance. 



Comparative Accuracy of Sworn and Unsworn Statements (Stern and Borsl) 





STERN 


STERN 


STERN 


BOHST 


1 Range 


Errors 


Range Errors 


Range 


Errors 


Range ; Errors 


Positive statements. . . 

Sworn statements 

Unsworn statements . . . 
Certain statements — 
Uncertain statements . 


(100) 
76 
. 24 


13.6 
11 
20 


(100) 19 
68 7 
32 — 


(100) 
70 
30 


23 

14 


(100) 11.0 
60 8.2 

40 ! 15.5 

97.5 10.1 

2.5 44.0 



Note. — All figures are in per cents. The results, save those of the third 
and fourth columns, refer to narratives, not depositions. 

(4) Accuracy and attestation. Generally speaking, attestation 
does not guarantee accuracy: on the contrary, though the num- 
ber of errors is nearly twice as great in unsworn as in sworn 
testimony (according to Stern, 1.82 times, according to Borst, 
1.89 times as great), there still remains as high as 10 per cent 
error in sworn testimony. These relations are shown clearly in 
Table 44. 

(5) Dependence on sex. In all of Stern's work, both in narratives 
and depositions, with pictures, or events, or estimations of times 
and distances, whether under oath or not, the reports of men have 
been more accurate (by from 20 to 33 per cent), though less 
extended, than those of women, and a similar sex difference has 



^ The reason for this lack of general relation between range and accuracy 
is presumably that there are two kinds of good witnesses — the one possesses 
good capacity of observation, recall and report, and hence exhibits a large 
range and a high degree of accuracy; the other is cautious, and therefore 
restricts his range, which may be poor at best. 



306 DESCRIPTION AND REPORT 

appeared in tests of school children. This superior accuracy of 
boys becomes more evident when the report is difficult to make. 
Stern's conclusions have, however, been criticized by both Wresch- 
ner and Miss Borst. Wreschner found that among adults women 
did better than men. Miss Borst likewise found women superior 
to men in accuracy and range, but inspection of her results shows 
that the superiority of women consisted in the fact that they 
returned a larger number of correct statements, and that the 
men did not make less accurate statements in their more limited 
reports. 

More specifically, Borst found that in the narrative the range of men was 
76 per cent, and in the deposition 8.3 per cent of the range of women, while 
the accuracy of men in both forms of report was approximately 96 per cent of 
the accuracy of women. 

There is a similar discrepancy between Stern and Borst with regard to the 
tendency to attestation : the former found that men swore to 71 per cent, and 
women to 85 per cent of their report, whereas the latter found that men 
^wore to 61 per cent, and women to but 59 per cent of their report. 

(6) Dependence on age. The reports of children are in every 
way inferior to those of adults: the range is small, the inaccuracy 
large, and, since the assurance is high, the warranted assurance and 
reliability of assurance are both very low. During the ages 7 to 
18 years, the range, especially the range of knowledge, increases 
as much as 50 per cent, but the accuracy, save in the deposition, 
does not increase as rapidly (20 per cent). This development of 
capacity to report is not continuous, but is characterized by rapid 
modification at the age of puberty. 

The one factor that more than any other is responsible for the 
poor reports of children is their excessive suggestibility, especially 
in the years before puberty.^ 

Stern has endeavored to analyze in part the development of the child's 
capacity to report, and has distinguished four stages: (1) the very young 
child enumerates only isolated objects or persons (Binet's enumerator type) ; 
(2) at about the eighth year, actions are reported more carefully; (3) during 
the years 9-10, attention is for the first time paid to spatial, temporal, 
and causal relations; (4) in a still later period, there appears the capacity 



* On''the general subject of children's reports, consult the work of Binet, 
Stern, Lobsien, Borst, and Pliischkc. 



TEST 32: FIDELITY OF REPORT 307 

to make a qualitative analysis of the constituent features of the objects 
reported. 

(7) Dependence on intelligence. We have as yet no conclusive 
experiments upon the relation between accuracy of report and 
general intelligence. 

(8) Defectives. The reports of defectives, paralytics, epileptics, 
the insane, etc., show, as one might expect, a very high degree of 
inaccuracy, even when the pathological condition is not seriously 
developed. Such persons are also highly suggestible (de Placzek). 

(9) Dependence on time-interval. Lengthening of the time-interval 
between experience and report exerts, as one might expect, a 
generally unfavorable influence, but there is nothing like the loss 
in efficiency shown in curves of memory for nonsense syllables, 
as in the familiar tests of Ebbinghaus: indeed, for some *S's the 
report seems to be somewhat improved after several days have 
elapsed, and, in general, the conditions are so complex as to demand 
further special investigation. 

TABLE 45 

Effect of Time-Interval on Range and Accuracy of Report (Borst) 



FOHM OF REPORT 


NARRATIVE 


DEPOSITION 


Intervals in Days .... 


I 3 


9 


3 


9 


Range 

Accuracy 


40.6 

89.5% 


39.6 

87.9% 


Per cent 
67.2 

82.6 


Per cent 

65.5 
83.4 



From his earlier tests, Stern computed a fairly constant decrease of 
accuracy with tin-e, amounting, on the average, to a loss of 0.33 per 
cent per day over the period of three weeks which he studied; similarly, 
Borst computed a decrease in accuracy of 0.27 per cent per day during 
a period of six days. Some of her results are presented in Table 46. 

Though range and accuracy seem thus to suffer with the lapse of time, 
assurance, as shown by the number of certain and attested statements, 
is not, it seems, equally affected, but shows either a surprising con- 
stancy, or, if anything, a tendency to increase. From this it may be 
concluded that assurance and tendency to oath are due to S's 'personal 
equation,' rather than to the freshness of his memory. It would follow, 
of course, that warranted assurance and warranted tendency to oath 
decline with the lapse of time. 



308 DESCRIPTION AND REPORT 

(10) Dependence on contents or features. Not all the features of 
the original experience are reported with the same frequency or 
with the same accuracy: there is, rather, a process of selection, 
both in the process of observation, and also, probably, in memory 
and in the formulation of the report. In general, we may say that 
persons and their acts, objects, things, and spatial relations are 
reported with considerable accuracy (85-90 per cent), whereas 
secondary features, especially quantities and colors, are reported 
with considerable inaccuracy (reports on color have an error of 
from 40 to 50 per cent). 

(11) Dependence on form of report. All authorities agree that 
the use of the interrogatory, whether of the complete or incomplete 
form, increases the range and decreases the accuracy of the report. 
Thus, in comparison with the narrative, the range of the interroga- 
tory may be 50 per cent greater, while the inaccuracy (of the incom- 
plete interrogatory) may be as much as 550 per cent greater. In 
general terms we may say that about one-tenth of the narrative is 
inexact, but about one-quarter of the deposition. Typical statis- 
tics are given in Table 46. 

TABLE 46 

Dependence of Report on its Form {Stern and Borst) 



RANGE 


ACCURACY 


! Narrative 

i 


Deposition 


Narrative 


Deposition 


1 

Stern 25.5 


52 1 


Per cent 
94 


Per cent 
67.1 


Borst 40.5 


65.6 


89 


83.0 



Note— In comparing these figures, it should be remembered that Stern 
used an incomplete, and Borst a complete interrogatory. 

(12) Depeyidence on the type of question. The introduction of 
leading or suggestive questions very noticeably decreases the 
accuracy of report for children, and, unless the conditions of report 
are quite favorable, even for adults. The greater suggestibility of 
children is shown by Stern's results in which the inaccuracy of 
boys and girls aged 7 to 14 was from 32 to 39 per cent, as against 
10 per cent inaccuracy for young men aged 16 to 19 years. Binet's 
results Avith suggestive questions have already hoon cited. 



TEST 32: FIDELITY OF REPORT 309 

(13) Dependence on the ideational type of the reporter. The best 
reports are given by observers of a mixed ideational type, e.g., 
acoustic-motor or visual-motor (Borst): even in a picture-test, 
the purely visual-minded observer is inferior, though less open to 
suggestion (Lobsien). 

A characteristic analysis of reports, for the purpose of classifying reporters 
into ideational types has been given in the description-of-an-object test 
(No. 31), in which Binet distinguishes four types of reporter — the observer, 
the describer, the emotionally-minded, and the erudite. Miss Borst was 
unable to use this classification, however, with her »S's. 

Another classification of reporters according to mental type was attempted 
by Miss Borst, who, after a preliminary tachistoscopic test, compared 
the reports of 'fixating' and 'fluctuating' S's, and concluded that /S's whose 
attention is of the 'fixating' type have uniformly the greater warranted 
assurance of report. 

(14) The effect of repeating a report. When S is called upon to 
make his report several times, the effect of this repetition is com- 
plex, for (1) it tends in part to establish in mind the items reported, 
whether they be true or false, and (2) it tends also to induce some 
departure in the later reports, because these are based more upon 
the memory of the verbal statements of the earlier reports than 
upon the original experience itself, i.e., the later reports undergo 
distortion on account of the flexibility of verbal expression. 

(15) The effect of practise. Simple practise in reporting, even 
without special training or conscious effort to improve, facilitates 
and betters the report, as is shown in Table 47, from Miss Borst. 
It will be noted that the tendency to oath and warranted tendency 
to oath are both particularly improved by practise, and that there 
is also an appreciable improvement in range, accuracy, warranted 
assurance, and reliability of assurance, whereas assurance and 
accuracy of assurance are scarcely affected. Similar practise- 
effects may be discerned in the deposition. From these results, 
it is clear that the several coefficients of report may vary more or 
less independently.^ 

1 There are needed, in the author's opinion, further experiments with 
careful introspective control by trained adults, so that we may secure a 
more adequate analysis of the factors that are affected by practise: the pre- 
vious investigators have relied too much upon mere statistical evaluation, 
whereas the field is now ripe for an introspective analysis of the mental 
operations concerned in report — an analysis that should, of course, make 
the utmost use of the statistical method for check and control. 



10 



DKSCKIP'noN AND KIOroK'l 



T/VBLE 47 
Effect of Prdctit^c upon Coefficients of Report (Narrative) {Borst) 



NIIMUEU OF UKI'OIIT (TKST) 




Range 

Accuracy 

Assurance 

Warranted assurance 

Heliahilily of assurance 

Accuracy of assurance 

Tendency to oath 

Warranted tendency to oath. . . 
Unwarranted tendency to oath 



llcliability of oath 93 . 



40.3 

88.2 
97.9 
88.0 



61.9 

57.5 

4.4 

93.0 



42.0 
90.0 
98.6 
89.0 
90.3 
99.2 
72.1 
66.5 
5.6 
91.7 



Note. — The clfect of practtise in tliese tests is soinewliat obscured by the 
fact that the hrst and tliird tests wore iiKuk; after a .'i-(hiy, the others after a 
9-day interval. 



(U)) The educabiUty of report. The capacity of children to 
observe and report in a detaiUnl and accurate manner may l)e 
inijM-oved by systematic training. This education may be best 
secured by app(^al to z(^al, interest, enthusiasm, or desire for im- 
provement on the part of th(^ child; more formal training of an 
intellectual type r.f/., suggestions for systematic observation, 
specific training in senscvperception, instruction designed to aug- 
ment appropriate apperceptive-masses, etc. — is much less effective. 

The inadequacy of the child's report is due, not so much to poor 
nuMuory, as to the fact that he fails to perceive many features in the 
original experience, that he fails to put into words even what he 
does perceive, and especiallj'' to the fact that he is absurdly un- 
critical (his assurance, indeed, commonly reaches 100 per cent). 



REFERENCES 

A. The most important singU^ source is Stern's Beitrdgc zur Psychologic 
der Aussage, ljv\\r/Atr, 1903 (1. Lack of space forbids the itemizing of the 
numerous titles: besides extended reviews, conununications, reports of 
lectures, etc., this ])eriodical contains imi)ortant articles by Stern, Jaffa, 
('ranier, Lobsien, ]ji])nuunv, Borst, Bogdanoff, Rodenwaldt, Oppenheim 
Kosog, Wendriner, (iiinther, (iottsohalk, and others. 



TEST 32: FIDELITY OK REPORT 311 

B. The followiiifi; aro other iiiiportanl ndcrcniccs. Sec No. 17 and especi- 
ally No. IS for bibliographies. 

(1) A. iJinet, La Suggestibility, Paris, 1900. Pp. 391. 

(2) A. Binet, La science du temoignage, in A. P., 11 : 1904 (1905), 128-137. 

(3) A. Binet, Psychologie individuelle. La description d'un objet, in 
A. P., 3: [1896] (1897), 296-332. 

(4) Marie Borst, Recherches exp'tlles sur Teducabilite et la fidelite flu 
t6moignage, in Ar. P., 3: 1904, 233-314. 

(5) Marie Diirr-Borst, Die Erziehung der Aussage und AnsclKuumg des 
Schulkindes, in E. P., 3: 1906, 1-30. 

(B) M. Borst and E. Claparede, La fidelite c.t reducabilite du trnioignage, 
in Arch, des sciences physiques et naturelles, April 7, 1904. 

(7) De Placzek, Exp. Untersuchungen liber d. Zeugenaussagen Schwach- 
sinniger, in Gross' Archiv f. Kriminalanthropologie, 18: 1904, 22-63. 

(S) O. Lipmann, Neuere Arbciten zur Psychologie der Aussage :Sainnielbe- 
richt, in Journ. f. Psych, u. Neurologie, 3: 1904, 245-249. 

(9) O. Lipmann, Die VVirkung der Suggcstivfragen, in Z. P. P., 8: 1906, 
89-96. 

(10) O. Lipmann, Die Wirkung v. Suggcstivfragen, in Z. A. P., 1 : 1907-S, 
44-92, 382-415, 504-546. 

(11) O. Lipmann, Praktische lOrgebnisse der Aussageforschung, in Z. 
P. P., 97-103. 

(12) M. Lobsien, IJebcr Psycli. der Aussage, in Z. P. P., 6: 1904, 161-209. 

(13) L. Maurer, Beobachtungc^n iiber das Anschauungsvermtigen der 
Kinder, in Z. P. P., 5: 1903, 62-85. 

(14). H. Miinsterberg, On the Witness Stand, N. Y., 1908. Pp. 265. 
(The several sections of this book have also appeared in magazine form, 
chiefly in McCIure's Magazine.) 

(15) L. W. Stern, Zur Psych, d. Aussage. I'jxp. Untersuchungen iiber 
Erinnerungstreue, in Zeits. f. d. gcs. Strafrcchtwissenschaft, 22: 1902 (also 
published separately, Berlin, 1902). 

(16) L. W. Stern, Literatur zur Psych, d. Aussage, in Z. A. P., 1 : 1907-8, 
429-450. 

(17) G. M. Whipple, The observer as rej)orter: a, survey of ihe 'psychology 
of testimony,' in P. B., 6: May 15, 1909, 153-170. 

(18) J. H. Wigmore, Professor Miinsterberg and the psychology of evi- 
dence, in Illinois Law Review, 3: Feb., 1909, 399 445 (with bibliography of 
127 titles). 

(19) A. Wreschner, Zur Psych, d. Aussage, in A. G. P., 1 : 1905, 148-183. 



CHAPTER IX 

Tests of Association, Learning, and Memory 

A generation ngo, tlie members of the 'English School' of psy- 
cliologists exalted 'association' as a fundamental principle or law 
ot mind comparable in its scope and importance with the law of 
gravitation in the material world. Whetlier this extreme position 
be iield or not, it must be admitted that the more complex phases 
of mental activity are more readily understood if certain basic 
principles of mental elaboration are posited, particularly the prin- 
ciples: attention, retention, and association. Disregarding the first 
of these, whicli we have already discussed, we find in retention 
the sine qua non of the development of human mental activity, and 
we find constantly at work in the conscious life of the organism a 
tendency for the establishment of connections between its con- 
current and its successive psychophysical activities. In so far as 
tile conscious organism acquires ncAv capacities for response, there 
must be retention and organization. Learning, retaining, recalling, 
associating, these are terms obviously descriptive of a series of 
related activities, and on this account, tests which deal with tliem 
are here assembled. 

The first three tests in this chapter investigate the nature and 
the efficiency of those associative connections that the subject has 
already established at the time of the experiment, whether the 
associative processes are allowed free rein, or are placed under cer- 
tain restrictions. The two learning tests investigate the subject's 
capacity to establish new associative connections, under relatively 
novel conditions. The memory tests, in a somewhat different 
way, investigate his retentive capacity or his ability to reproduce 
an arbitrary series of symbols or a series of related ideas. 

Association and memory, taken together, have undoubtedly 
been the occasion of more numerous and more elaborate experi- 
mental investigations than any other phase of mental life. Learn- 



TP:ST 33: UNCONTROLLED ASSOCIATION 313 

ing, in the narrower sense, has, perhaps, received somewhat less 
attention, though of late the importance of its application to peda- 
gogical problems has stimulated work upon it. 

The experimental study of associative activity can be, and has 
been, undertaken for quite varied purposes, e. g., to examine the 
time relations of mental phenomena, to study individual differences 
in thought-processes, as conditioned by age, sex, training, physi- 
cal condition, and the like, to analyze the diurnal curve of psycho- 
physical efficiency (as in Kraepelin's use of computation) , to diag- 
nose mental content, and even to reveal obscure mental tenden- 
cies and motives or intentionally withheld information (diagnos- 
tic association tests). Space forbids the exploitation of all the 
tests that have been developed in these fields, but a study of the 
more common tests of learning, association, and memory that have 
been selected for treatment here as being most applicable to the 
experimental study of school children, will serve to indicate the 
lines along which variant methods maybe developed and employed. 

TEST 33 

Uncontrolled association (continuous method) — The essence of 
this test is the requirement to write or pronounce an extended 
series of words not in the form of sentences. Its interest lies, first, 
in the difference of facility exhibited by different S's in the pro- 
duction of such a series of terms; secondly, in the nature of the 
terms given by S's of different sex, age, or social condition ; and 
thirdly, in the nature of the mental processes underlying the 
word-naming process. 

Cattell and Bryant (3) make brief mention of the test; Jastrow 
(5, 6), and later Miss Nevers (7) Miss Calkins (2), and Miss Tan- 
ner (8), employed it for the study of the community of ideas of 
men and women, Flournoy (4) for the study of the effect of environ- 
ment, present and immediately past, upon the course of associa- 
tion, and Binet(l) for the study of individual differences in intel- 
lectual processes. 

Materials. — Stop-watch. Blank forms containing numbered 
spaces for 100 words. 

Method. — Give S these instructions: "When I say 'now,' I 



314 ASSOCIATION, LKAUNING, AND MEMORY 

want you to start in with some word, any one you like, and keep 
on saying words as fast as you can until you have given a hundred 
different words. You may give any words you like, but they must 
not be in sentences. I will tell you when to stop." E starts the 
stop-watch at the connnand ' now' and writes on the prepared form 
the words spoken by *S. With mature >S's, it may be possible to 
get nothing more than scant abbreviations for the more rapid por- 
tions of the series, but these may be filled out subsequently. At 
the 100th word, stop the watch and record the time. If the time 
permits, and S can do so, it is advisable at once to go over his series 
and make marginal notes of all tlie intermediate links and subsid- 
iary associative processes that he can recall. 

Variations of Method. — (1) For group tests, £' may provide 
each »S with a blank containing 100 numbered spaces. Allow 3 
min. for writing, and rate speed in terms of number of words writ- 
ten. 

(2) E may omit the instruction to write or to speak as rapidly as 
possible, and allow *S to work at his leisure. This method, which 
was followed by Miss Nevers, is perhaps more satisfactory for the 
subsequent qualitative report upon the series, but deprives the 
test of whatever quantitative merits it possesses, besides tending 
to yield results of a distinctly different nature that are not compar- 
able with those otherwise obtained. 

(3) When working with younger *S's, E may with advantage 
limit the length of the series. Thus, Flournoy demanded but 10 
words, while Binet recorded the time for three series of 20 words 
each, and occupied the intervals in reviewing with »S the terms 
of the preceding series. This method is less fatiguing, and enables 
immature ^'s to give a more satisfactory account of their associa- 
tive connections, but it does not test (S's capacitj^ as rigorously 
as the longer list. 

(4) E may secure a very limited measure of uniformity in the 
earlier portion of the series by starting all /S's from the same word. 
For this, the words quick and play are recommended. Here it is 
of interest to observe tlie lin(\s of divergence in association taken 
by .different *S's. 

(5) Another variation is that of Flournoy, who, in addition to the 
word test, gave 45 »S's instructions to make 10 drawings of any sort. 



TEST 33: UNCONTROLLED ASSOCIATION 315 

Treatment of Data. — In the standard form of test, S's speed 
is indicated directly by his time for naming 100 words. In the 
group test, it is customary, similarly, to rate >S's speed in terms of 
words written in 3 min. It is not possible, however, to regard the 
times obtained from these two forms of the test as interchangeable, 
since the second form includes writing and this, as is demon- 
strated below, tends, even in the case of mature *S's, to slow the rate 
of performance. In so far, too, as *S's differ in their speed of writ- 
ing, this fact enters as an unavoidable disturbing factor in the 
group test. 

For qualitative comparison of the lists, E may, by inspection, 
supplemented by »S's explanations, catalog the words, either in the 
7 categories used by Binet, or in the 25 categories used by Jastrow 
and Miss Nevers. Both classifications are embodied in the re- 
sults below. 

Results. — (1) In tests of college students, Jastrow found an 
average time of 130 sec. for oral, and 308 sec. for written lists of 
100 words. Since writing an equal number of words from dicta- 
tion took 212 sec, Jastrow concludes that, in naming 100 words, 
aljout 1.14 sec. is used, on the average, in thinking the associa- 
tion between one word and the next. 

(2) Inspection of the lists printed both by Jastrow and by Binet 
shows that S's follow what might be termed a series of themes: 
a number of terms are written, all of which cluster about a common 
central idea; through one of these terms access is given to a new 
central idea, which in turn becomes a theme for the next series of 
terms; thus, in the series hand, face, lip, chest, knees, calf, cow, 
horse, pig, etc., the transition from the parts-of-the-body theme 
to the animal theme is effected by the common term calf. 

(3) In some S's, the controlling theme is an auditory sequence, 
which occasions long series of rimed or alliterative terms, e.g., 
run, pun, fun, etc., or hen, hand, head, harp, etc. 

(4) In this test, the most common words, i. e., those most easily 
got at, or those that lie, as it were, on the surface, are given 
first. After these are delivered, the task grows more difficult; 
deeper and more remote-lying terms must be actively sought 
for. Closely related to this is the fact that, at least in the lists 
of younger *S"s, practically all the terms are nouns. This is par- 



'Mi') ASSOCIATION; LEARNING, AND MEMORY 

ticularly the case in the short series conducted by Binct, so that, 
as he remarks, the test, as he conducted it, is virtually equivalent 
to a request to write 20 common nouns. 

(5) In view of the vast number of words available, it is at first 
surprising to note the degree of community present in lists of 100 
terms given by a limited number of persons. Thus, Jastrow found 
that in 50 lists (5000 words), only 202-4 words were different, only 
1266 words occurred but once, while the 100 most frequent words 
made up three-tenths of the whole number. 

These most frequent words are, as has just been said, names of 
common objects: in Jastrow's 50 lists, the following were the most 
frequently used words: hook (40), horse (37), girl (35), man (34), 
ban (33), table (30); then follow chair, tree, cow, paper, dress, etc., 
in somewhat lesser frequency. 

(6) For the classification of the words given by 20 12-year old 
pupils, Binet found seven categories adequate, viz: (a) names of 
objects in the room where the test was held, (h) parts of the per- 
son or clothes, (c) objects or persons in the school, (d) objects 
recalled from the home, (e) objects seen in the streets (horse, 
tree), (/) objects seen in fields or on country excursions, (g) un- 
classified nomis. Here there is no place for abstract terms, many 
of which were found in series given by American pupils in Jastrow's 
tests. Jastrow's owm classification is indicated in Table 48, where 
it Avill be seen that his 25 categories are much more elaborate and 
extended than those employed by Binet. 

(7) The question as to sex difference in spontaneous trains of 
ideas such as are evoked in this test has been answered differently 
by the tests conducted at Wisconsin University and at Welleslej' 
College. The comparison of Wisconsin men and Wisconsin women 
was made by Jastrow, the 1894 test of Wellesle}- women b}' ]Miss 
Nevers and with no instruction as to speed, the 1896 test of Well- 
esley women by Miss Calldns but with the same instructions as 
those of Jastrow. The categories of particular interest are those 
printed in italics. Jastrow's results in this and other tests led him to 
believe that "the women repeat one anothers' words much more 
than the men." He found that "the class to which women contri- 
bute most largely is that of articles of dress, one word in every eleven 
belonging to this class. The inference from this that dress is the 



TEST 33: UNCONTROLLED ASSOCIATION 



317 



Distrihution of Terms in ' Uncontrolled' Association {Jastrow, Nevers, Calkins) 
{Each column represents 25 lists of 100 words each.) 



CATEGORIES 



1 . Animal kingdom 

2. Wearing apparel and I 

fabrics 

3. Proper names I 

4. Verbs | 

5. Implements and utensilsj 

6. Interior furnishings I 

7. Adjectives j 

S. Foods I 

9. Vegetable kingdom. . . 

10. Abstract terms 



11. Buildings and building 

materials 

12. Parts of body 

13. Miscellaneous 

14. Geographical and land- 

scape features 

15. Mineral kingdom 



IG. Meteorological and as- 
tronomical 

17. Stationery 

18. Occupations and callings 

19. Conveyances 

20. Educational 

21. Other parts of speech. ... 

22. Arts 

23. Amusements 

24. Mercantile terms 

25. Kinship 



WISCONSIN 


WISCONSIN 


WELLESLEY 


WELLESLEY 


MEN 


WOMEN 


WOMEN, 1896 


WOMEN, 1894 


254 


178 


146 


223 


129 


224 


97 


96 


194 


153 


81 


141 


197 


134 


279 


114 


169 


121 


139 


132 


89 


190 


212 


84 


177 


102 


300 


234 


53 


179 


88 


56 


121 


110 


101 


91 


131 


97 


101 


280 


105 


117 


86 


106 


101 


105 


66 


34 


91 


97 


123 


162 


97 


80 


70 


142 


74 


96 


30 


54 


85 


76 


109 


26 


60 


86 


69 


26 


71 


47 


24 


33 


62 


52 


19 


79 


34 


76 


102 


167 


96 


5 


164 


41 


33 


61 


17 


44 


30 


53 


17 


102 


30 


29 


18 


15 


17 


32 


42 

1 


18 



predominant category of the feminine (or of the privy feminine) 
mind is valid with proper reservations." Since the women exceed 
the men in the enumeration also of foods, amusements, arts, and 



318 ASSOCIATION, LEARNING, AND MEMORY 

educational matters, but fall below them in naming implements 
and utensils, professions, and especially in abstract terms, Jastrow 
concludes, "that the feminine traits revealed in this study are an 
attention to the immediate surroundings, to the finished product, 
to the ornamental, the individual, and the concrete, while the mas- 
culine preference is for the more remote, the constructive, the useful, 
the general, and the abstract" (5; pp. 564-5). Mostof these conclu- 
sions are flatly opposed by the Wellesley results of 1894, but the 
employment of identical methods in the 1896 test prodticed less 
marked divergencies. It is particularly to be noted that writing 
at a faster rate (1896 test) caused a marked decrease in the n amber 
of abstract terms, and brought the terms relating to 'interior 
furnishings' up even beyond those of the Wisconsin women; on 
the other hand the frequency of terms for 'wearing apparel' was 
not affected by this change in method. 

These discrepancies raise the issue, as Miss Tanner has pointed 
out, whether this test can be expected to reveal fundamental native 
differences in mental constitution of the two sexes, or whether it 
reveals merely acquired traits, social traditions, individual habits, 
educational, and other environmental influences. The lists 
written by college students might be expected, for example, to be 
considerably affected by their recent occupations, courses of study 
pursued at the time, etc. 

(8) This influence of environment upon the lists of associations is 
indicated particularly in Flournoy's brief tests (10 words and 10 
drawings), the results of which are summarized in Table 49. 

TABLE 49 
Influences that Affect ' Uncontrolled' Series of Words or Drawings (Flournoy) 



Traced to present surroundings 

Traced to the immediate past 

Due to the milieu 

Traced to recent personal experiences . 
Traced to personal habits 

Expressing individuality 

Unexplained 



DRAWINGS 


WORDS 


per cent 

13.8 

1.9 


per cent 

29.0 

8.2 


15.7 


37.2 


2.4 
39.2 


3.9 
9.2 


41.6 


13.1 


42.7 


49.7 



TEST 34: CONTROLLED ASSOCIATION 319 

REFERENCES 

(1) A.Binet, L'Etude experimentale de I'intelligence, Paris, 1903. Pp. 
309. Especially chs. ii. to iv. 

(2) Mary W. Calkins, Community of ideas of men and women, in P. R., 3: 
1896, 426-430. 

(3) J. McK. Cattell and Sophie Bryant, Mental association investigated 
by experiment, in Mind, 14: 1889, 230-250. 

(4) Th. Flournoy, De Taction du milieu sur I'ideation, in A. P., 1: 1894 
(1895), 180-190. 

(5) J. Jastrow, A study in mental statistics, in the New Review, 5: 1891, 
559-568. 

(6) J. Jastrow, Community of ideas of men and women, in P. R., 3: 1896, 
68-71, 430-1. 

(7) Cordelia Nevers, Dr. Jastrow on community of ideas of men and 
women, in P.R., 2: 1895, 363-7. 

(8) Amy Tanner, The community of ideas of men and women, in P. R., 3 :, 
1896, 548-550. 



TEST 34 

Controlled association: part-wholes, genus-species, and oppo- 

sites. — The common features of these tests, which are characterizied 
by their users as tests of "abihty to appreciate relationships and to 
control associations," is the demand for the execution of a verbal 
association which is so restricted that only a very limited number 
of words may be considered as correct associates. The restric- 
tion is less stringent in the part-wholes and genus-species than in 
the opposites test. On account of this restriction of connection, 
the tests may be said to occupy a ground intermediate between the 
uncontrolled series illustrated in the preceding test, and the strictly 
controlled associations involved in the computation tests that fol- 
low. The three tests have all been elaborated at Columbia Uni- 
versity. Examples of their use may be found in Miss Norsworthy 's 
tests of feeble-minded children (2), in Thorndike's study of the 
degree of resemblance of twins (5), and in the examination of cor- 
relations of perceptive and associative processes by Aikins, Thorn- 
dike, and Hubbell (1). 



320 ASSOCIATION, LEARNING, AND MEMORY 

A. THE PART-WHOLES TEST 

Materials. — Stop-watch. Printed form containing the ten 
nouns mentioned below, and provided with spaces for the recording 
of an equal number of associates. 

Method. — Instruct S as follows: "I shall give you a paper on 
which are printed ten words. I want you, as rapidly as you can, 
to give for each word the name of the whole thing of which the 
word is a part. For instance, if the word/i(r were given, you w^ould 
be asked to name a thing that fur is a part of, like cat; iorha7idyou 
might say arm or watch. To make sure you understand, give me a 
'whole' for mercury — for drawer." If S displays proper compre- 
hension of the test, give him the printed list of test-words; start the 
stop-watch as he glances at the first word; write down his asso- 
ciates on a separate blank as fast as given, and record the total time. 

Variations of Method. — (1) For a group test, each S is sup- 
plied with the printed blank and is requested himself to write the 
associates after each test-word. To retain the measure of speed 
as well as accuracy of association, the test must be conducted with 
a time-limit such that the fastest S in the groups to be tested can 
but just finish the ten words. This unavoidable introduction of 
writing necessarily makes the quantitative results differ from those 
obtained by oral report. 

(2) Following the procedure adopted by Miss Norsworthy, the 
group-test may be given with no time-limit: here efficiency is 
figured entirely on the basis of qualitative performance. 

Treatment of Data. — (1) When time is recorded, speed is 
measured directly in seconds, or in words, according as the test 
is given to individuals or to groups. It Avould, perhaps, be possible 
to combine speed and accuracy in a single index of efficiencj^ after 
the methods described in the Cancellation Test (No. 26.) Sugges- 
tions for other methods of computing net efficiency are given in 
the discussion of the opposites test. 

(2) The method of scoring used by Miss Norsworthy is, in the 
author's opinion, somewhat open to criticism, but it is reproduced 
here in order that E's may compare their results with her published 
norms. Her scores arc based simply upon the number of asso- 
ciates correctly given. A perfect score is, therefore, 10. The key 
employed is as follows : 



TEST 34: CONTROLLED ASSOCIATION 



321 



ASSOCIATES 
WORD DEEMED CORRECT. 

Door Anything that usually has a (h)or 

Pillow Couch, bed Sofa 

Letter Word, alphabet, envelope 

Leaf Tree, plant, book 

Button Anything usually having buttons 

Nose Face, head Cheek 

Cover Book, bed, kettle 

Page Book 

Engine Train, car 

Glass Window, door Tumbler 

This key is, of course, not exhaustive, but simply illustrative. 

Results. — (1) Table 50 represents the performance of 504 
normal children, aged 8 years and over, as reported by Miss Nors- 
worthy.i Sex-differences are not sufficiently evident to justify 
separate treatment. 

TABLE 50 
Normal Performance in the Part-Wholes Test (Mors worthy) 



AGE 


1 8 


9 


10 


11 


12 


13 


14 


15 


16 


ADULTS 


Median 
P. E. 


6.5 
2.3 


7.8 
1.3 


7.8 
1.9 


8.7 
1.1 


8.7 
1.2 


9.0 
0.7 


9.0 
0.7 


9.0 
0.7 


9.0 
0.7 


10.0 
0.5 



(2) Defective children, according to the same writer, are dis- 
tinctly inferior to normal children in this test : thus the percentage 
of normal children with a record above the median, above -1 P.E., 
and above -2 P.E., would of course, be 50, 75, and 91, respectively, 
but the percentages of feeble-minded children obtaining these three 
grades of efficiency were but 9, 17, and 27, respectively. That is, 
only 9 per cent of the feeble-minded children reached the degree 
of efficiency attained by one-half of the normal children, etc. 

B. THE genus-species TEST 



Materials. — As in the part-wholes test, but with a different 
list. 

^ These norms are perhaps unduly high in some cases, since three of the ten 
test-words were actually given as examples before the test was administered. 



322 



ASSOCIATION, LEARNING, AND MEMORY 



Method. — Instruct S as follows: "I shall give you a paper 
on which are printed ten words. I want you, as rapidly as you 
can, to give for each word the name of some particular thing, the 
class name of which is given, i.e., you are to give some species of 
the genus meant by the given word. For instance, if the word 
animal were given, you would be expected to name some one kind 
of animal, like horse, or if the word verb were given, you might 
give 7-un as a particular verb. To make sure you understand, give 
me a word for something in the class named by the word man. 
Give me a 'species-associate' for money. ^^ When S is clear as to 
what is wanted, the test is administered in the same manner as the 
part-wholes test. 

Variations of Method. — The same variations may be adopted 
as in the part-wholes test. 

Treatment of Data. — (1) Speed or rate of performance is 
computed as in the part-wholes test. 

(2) The method of scoring adopted by Miss Norsworthy, which 
is the one on which the results below are based, takes account only 
of the number of correct associates written. In general, any spe- 
cific term that falls under the class term is counted as correct. 
The word play was not allowed under toy, nor the word toy under 
game. 

Results. — (1) Table 51 represents the performance of normal 
children, based on the examination of 511 children of both sexes. 

table 51 
Normal Performance in the Genus-Species Test (Norsworthy) 



AGE 


8 


9 


10 


11 12 


13 


14 


15 


16 ' 


ADULTS 


Median 
P. E. 


5.0 
2.0 


5.0 

2.7 


7.0 
2.9 


9.2 : 9.2 
1.9 0.7 


9.3 
0.4 


9.3 
0.5 


9.5 
0.5 


9.5 1 
0.5 


10.0 
0.0 



(2) Feeble-minded children are distinctly inferior in this test to 
normal children of the same age : only 9 per cent reach the median 
of the normal children, only 16 per cent reach — 1 P.E., only 17 
per cent reach — 2 P.E. of normal children of their age. 



TEST 34: CONTROLLED ASSOCIATION 



.323 



C. THE OPPOSITES TEST 



Materials. — Stop-watch. Printed forms embodying one or 
all of the following lists, with blank spaces for the recording of 
associates. 

List A is No. 1 and List B is No. 2 as used by Miss Norsworthy for testing on 
two successive days. List B is also the one mentioned by Thorndike in his 
study of twins and elsewhere, also by Aikins, Thorndike and Hubbell. The 
last-named investigators used List C for their so-called 'hard-opposites 
test.' These three lists have the advantage of extended use, so that norms 
can be stated for them with some confidence. Wells, however, contends that 
they contain unequally difficult stimulus-words, and proposes several other 
lists, one of which is as follows: High, heavy, up, worse, few, true, east, 
wrong, wet, asleep; another ten-word list suggested by Wells is : after, sick, 
smooth, early, large, open, good, weak, long, glad. 



LIST A. 

bad 

inside 

slow 

short . 

little 

soft 

black 

dark 

sad 

true 

dislike 

poor 

well 

sorry 

thick 

full 

peace 

few 

below 

enemy 



LIST B. 

good 

outside 

quick 

tall 

big 

loud 

white 

light 

happy 

false 

like 

rich 

sick 

glad 

thin 

empty 

war 

many 

above 

friend 



LIST c. 

stupid 

hard-working 

strong 

sane 

obnoxious 

foolish 

handsome 

adroit 

superior 

loquacious 

rapid 

generous 

straight 

separate 

up 

always 

joy 

high 

obscure 

proud 



Method. — Instruct ;S as follows: "I shall give you a paper on 
which are printed 20 words. I want you, as rapidly as you can, to 
give for each word, a word that ineans just the opposite to it, that 
is, a word that means just what the printed word doesn't mean. 
For instance, the opposite to day is night, the opposite to front is 
back. To make sure you understand, give me an opposite for old — 



324 ASSOCIATION, LEARNINCx, AND MEMORY 

for sharp." If S has difficulty, E may seek other means for mak- 
ing the nature of the test clear, e.g., "If a man isn't sick, what 
s he?" "One road is long, another might be what"?, etc. The 
test is then administered in the same manner as the part-wholes test. 

Variations OF Method. — ^Thesame variations may be adopted 
as in the part-wholes test. To test the effect of practise, a reverse 
series may be given immediately after the test or, say, on the fol- 
lowing day. List B, it is evident, is a reverse of List A, and was 
used by Nors worthy in the manner just mentioned. 

The last-named investigator allowed 60 sec. for the opposites 
test in her study of feeble-minded children, after three of the words 
on the list had had their opposites given for illustration. Thorn- 
dike also gave 60 sec. for the test, but Aikins allowed only 30 
sec. for either List B or List C. It is to be remembered that in all 
these cases the associates were written. The better method is that 
prescribed : oral response by individual S's, timed by E. 

Treatment of Data. — Various plans have been followed in 
scoring this test, some of which seem needlessly complicated and 
artificial. The simplest plan is rank *S's in terms of speed (time 
needed or words written in a limited time) and in terms of accuracy 
(percentage of correct opposites). If time is neglected, *S's may be 
scored by simply subtracting the number of wrong associates from 
the number of right associates, neglecting possible instances in 
which no associate is given.^ 

A modification of this simple method of scoring which will admit 
of giving partial credit for some associates that are not strictly 
correct, yet not wholly wrong, is illustrated in the work of Miss 
Norsworthy, who allowed a credit of 1 for each correctly given 
associate and 0.5 for partially correct associates. The correct 
associates for List A are the terms of List B, and vice versa. In ad- 
dition to these words, certain other terms are allowed either full 
credit or half credit, as indicated herewith. 



STIMULDS 

inside 

slow 

short 

1 This is the method of scoring represented in Thorndike's curve of dis- 
tribution for this test (4: p. 49), and used by the same author in his study of 
mental resemblances in twins. 



ASSOCIATES 


ASSOCIATES 


CREDITED WITH 1. 


CREDITED WITH 0.5 




out, outdoors 


fast 


quickly 




big 



TEST 34: CONTROLLED ASSOCIATION 



325 



ASSOCIATES 


ASSOCIATES 


CREDITED -WITH 1. 


CREDITED WITH 0.5 




tall 


hard 


rough 


daylight 




glad 






falsehood 


love 




ill, badly 




happy 




a lot 




over, on top 




companion 






in, indoors 




lazy, slowly 




little, low 


short 




low 


whisper 


sorry 


sorrow 




right, truth 


unlike, disliked, 




different, hate 




healthy 




mad 






broad 


filled 




one 




under 





little 

soft 

dark 

sad 

true 

dislike 

well 

sorry 

few 

below 

enemy 

outside 

quick 

tall 

big 

loud 

happy 

false 

like 

sick 

glad 

thin 

empty 

many 

above 

In the limited-time method adopted by Aikins (30 sec. per list), scor- 
ing was effected in terms of five quantities: (l) the point reached in th^ 
tpst, (2) the number of associates written, (3) the number of errors, (4 
the percentage of errors to the number done, and (5) a general index 
(aet efficiency), calculated in the hard-opposites test (List C) by sub- 
t rafting twice the number of errors from the number known, multiplying 
the remainder by 2, and subtracting the number of omissions, and in the 
easy-opposites test in the same manner, save that 3 times the number 
of errors were subtracted. 

Results. — (1) The performance of normal children for Lists 
A and B, as scored by Miss Norsworthy, is indicated in Table 52. 

(2) Sex differences cannot be made out with certainty.^ 

(3) In (ion\Y>'^Ymg feeble-minded with normal children, the former 
are found markedly inferior. No feeble-minded child, according 



See also Thorndike (3, p. 117). For the distribution of 239 cases of 12.5 
year old children, see the same author (4, Fig. 32, p. 49). 



326 



ASSOCIATION, LEARNING, AND MEMORY 



Normal Performance in the Opposites Test. Both Sexes. 605-608 Cases 
{Nor swarthy) 



FIRST LIST 



SECOND LIST 



8.0 


7.4 


2.0 


8.7 


1.4 


9.0 


9.0 


2.0 


9.5 


1.7 


10.0 


9.9 


3.0 


11.5 


2.2 


11.0 


12.5 


3.0 ^ 


13.1 


2.9 


12.0 


13.5 


2.6 


14.7 


3.6 


13.0 


14.0 


2.5 


16.4 i 


2.4 


14.0 


14.5 


2.3 


17.8 


2.0 


15.0 


15.0 


2.3 


18.5 


2.0 


16.0 


15.5 


2.3 


19.0 


2 


Adults 


20.0 


1.0 


20.0 

1 


1.0 



to Miss Norsworthy's tests, reached the level of the median per- 
formance of normal children of his age, only about 1 per cent were 
better than — 1 P.E., and only 6 per cent better than — 2 P.E. 
of normal children of their age. 

(4) There is a high degree of correlation (r = 0.90, P.E. about 
.05) between the capacity of twins, as measured by Thorndike. 

(5) The degree of correlation between the opposites test and related 
tests, as measured by Aikins, Thorndike, and Hubbell, is shown in 
Table 53. 

Notes. — Another relatively easy, though strictly controlled, 
association test is that of the backward-alphabet. This may be 
conducted in the same manner as the tests just described, by asking 
S to name, or to write as rapidly as possible, the letters that pre- 
cede /, A;, s, p, w, I, e, r, d, o, v, j,n, t, and h. For comparison, and 
to obtain a rough notion of S's familiarity with the sequence of the 
alphabet in general, this test might be supplemented by another 
in which S was required to name or to write as rapidly as possible 
the letters that follow another series of 15 letters. For a written, 
group test, Aikins, Thorndike, and Hubbell allowed 15 sec. for 
the backward-alphabet test. 

The same investigators combined the performances of *S's in the 



TEST 34: CONTROLLED ASSOCLITION 327 



Correlation^ of Opposiies Test wltli Other Tests {Alkins,Thorndike and 
Huhhell) 





FIRST MEMBER 




1 SECOND MEMBER 


COBREIiAlION 
IN PER CENT 


ListC 








.50 


List C. 


Number done 




.Alphabet. Number done 


19-22 


List B. 


Number done . 




.Alphabet. Number done 


40-50 


List B. 


Percentage of 


errors . 


..List C. Percentage of errors.. . 


20 


List B. 


Percentage of 


errors . 


. Alphabet. Percentage of errors 


40 


List C. 


Percentage of errors . . 


. Alphabet. Percentage of errors 


10 


List B 






List C Net efficiency 


40 


List B. 


Net efficiency. 




. Alphabet. Net efficiency 


60 


List C. 


Net efficiency. 




.Alphabet. Net efficiency 


34 



easy-opposites, hard-opposites, and backward-alphabet tests by 
ascertaining for each S: (1) the total number done (associations 
made), (2) the total number of errors, (3) the ratio of (2) to (1), 
(4) the total number of correct associations, and (5) the total net 
efficiency (by adding the efficiency scores in the hard-opposites 
and alphabet tests to one-half the net efficiency in the easy-oppo- 
sites test) . 

REFERENCES 

(1) H. A. Aikins, E. L. Thorndike, and Elizabeth Hubbell, Correlation 
among perceptive and associative processes, in P. R., 9: 1902, 374-382. 

(2) Naomi Norsworthy, The psychology of mentally deficient children, 
New York, Nov.. 1906. Pp. 111. 

(3) E. L.Thorndike, Educational psychology. New York, 1903. Pp. 173. 

(4) E. L.Thorndike, An introduction to the theory of mental and social 
measurements, New York, 1904. Pp. 210. 

(5) E. L.Thorndike, Measurements of twins, in Arch, of Phil., Psy., etc. 
No. 1, Sept., 1905 (Columbia Contr. to Phil, and Psych., 613 No. 3). Pp. 64. 

TEST 35 

Controlled association: Computation. — The solution of simple 
arithmetical problems in addition, subtraction, multiplication, and 

1 The correlations represented in this Table were figured by a special 
method, illustrated in Aikins (1 : p. 381) 



328 ASSOCIATION. LEARNING, AND MEMORY 

division may be considered as essentially dependent upon the accu- 
racy and rapidity with which the appropriate associative processes 
are executed. Computation is, therefore, a test of controlled asso- 
ciation in which the restriction of the associative sequence is com- 
plete, in which only a single outcome is correct. But numerous 
subsidiary activities are, of course, involved. Thus, the solution 
of arithmetical problems with the aid of paper and pencil demands, 
besides associative activity, both visual perception and motor 
activity, while mental computation imposes an additional tax b;y 
necessitating the holding in mind of the problem itself and of the 
various steps in its solution. 

Because of this implication of perception, movement, attention, 
retention, and perhaps other forms of mental activity, as well as 
simple associative activity, the computation test has been em- 
ployed not merely for the special purpose of studying the nature 
and course of associative processes, but also for the more general 
purpose of investigating mental efficiency atlargeigeistige Leistungs- 
fdhigkeit). Oehrn (19), for example, who was one of the first 
to use computation as a mental test, sought to study individual 
differences in the nature of associative processes, Aikins, Thorn- 
dike, and Hubbell (1) and Krueger and Spearman (15) to study 
the correlation of specific mental functions, Thorndike (27) to 
determine the relative influence of heredity and environment upon 
mental efficiency, Reis (21) to compare the ability of normal, par- 
alytic, and hebephreniac children, Jones (10) to investigate the 
effect of bodily posture, and Vogt (29) the effect of distraction, 
upon mental efficiency. But the commonest application of the 
computation test has been made in the formulation of the curve of 
mental efficiency, or the work-curve (Arbeitsktirve) , with special 
reference to the influence of practise, rest-pauses, exercise, and sim- 
ilar factors upon the mental efficiency of children during a school- 
day. This use of the test is illustrated in the work of Bellei(2), 
Burgerstein (3), Ebbinghaus, (6) Friedrich (8), Holmes (9), 
Keller (11), Kemsies (12), Laser (16), Marsh (17), Schulze (22), 
Teljatnik (24), Thorndike (25), and Winch (28), as well as by 
numerous investigations in Kraepelin's laboratory.^ 

' See for this work the various volumes of the Psychologische Arbeiten. 



TEST 35: COMPUTATION 



329 



Addition, inultiplication, and bothin alternation, have been more 
popular forms of computation than subtraction or division. With 
all four forms, varied types of problems have been used. These 
variations in the ai;rangement of the test naturally affect its out- 
come. The most important types of test are illustrated herewith. 
Beside the types that are shown, Winch employed miscellaneous 
arithmetical problems, while Reis had his *S's add mentally for 1 
min. })y 7's or by 12's. 

Examples of Material Usedin Computation Tests 



A 


B 


c 4 : 


2 


4 


7 5 


s 

9 


I 
3 


1 ; 


7 


5 


D 


4 


2 


95799 


8 


6 


86967 


9 


4 


32687 


5 


3 


84799 


1 


4 


95976 


7 


6 


34797 





1 


97864 


2 


5 


98945 


6 


4 


87824 


3 


2 


68792 


5 


I 


79867 


1 


2 


8S896 


3 


3 


97745 


9 


6 


39799 


2 


r> 


48970 


1 


3 


89043 


3 


6 


67354 


6 


5 


54628 


9 


1 


91176 


S 


2 


9025 


3 






5 






2 






7 














2 8 3 2 9 9 5 4 

9 J 9 3 8 3 8 J 

1 2 etcT 

G H 64293643194831457627 

93 38682725423585791858 

68 ' '^ 

41 L 364 M 47 N 948 O 7986 R 4)7G[) 

25 X6 X89 X 579 X 4523 

52 



5 4 3 17 
5 5 13 9 


E 42 
+79. 


F 492 
+763 


157627 I 982 
91858 -469 


J 64 
-27 


K 28 

X 8 



P 428423995479253314325 
4 



Q 254) 46592341 



330 ASSOCIATION, LEARNING, AND MEMORY 



EXPLANATORY 



Addition 



A. Vertical series of 1-pIace numbers, ai'ranged to avoid repetitions and 
pairs adding to 10. S's drop back to units when each hundred is reached. 
Oehrn, Vogt, and others working under Kraepelin used columns of as many 
as 7,000 of such digits. Krueger and Spearman used 70, grouped by lO's 
as illustrated. Marsh used similar columns of 15 or 25 digits. 

B. Vertical column of 24 1-place numbers, using 1 to 6 only. Used by 
Jones, who had S add aloud while he himself followed with a check list. 

C. Horizontal series of 1-place pairs of digits. A modification of the 
Kraeplin 1-place series in order to make possible the examination of the ac- 
curacy of each addition. The right-hand figure of the sum is the only one 
recorded, as illustrated in the first four problems. Used by Schulze, and 
apparently also by Ebbinghaus and by Vogt. 

D. Twenty 5-place numbers. Used by Thorndike. 

E. Two 2-place numbers. Used by Teljatnik. 

F. Two 3-place numbers. Used by Kemsies for mental addition. 

G. Five 2-place numbers. Twenty such problems were given and 2 min. 
allowed for computation. Used by Thorndike and by Aikins, Thorndike 
andHubbell. 

H. Two 20-place numbers. Used by Burgerstein, Laser, Friedrich, and 
Holmes. The last-named investigator published elaborate rules for the 
construction of these problems in such a way as to avoid the extension of 
errors in 'carrying.' She used 4 blanks with 16 such problems on each 
blank. 

Subtraction 

I. Two 3-place numbers. Used by Kemsies for mental subtraction. 
J. Two 2-place numbers, to be written on the blackboard (Teljatnik). 



Multiplication 

K. Two-place multiplicand, 1-place multiplier. Used by Kemsies for 
mental computation, and by Ebbinghaus for written group tests. 

L. Three-place multiplicand, 1-place multiplier. Used by Kemsies. 

M. Two-place multiplicand, 2-place multiplier. Used by Keller, and by 
Marsh with the digits 1, 2, 5, and 9 excluded. 

N. Three-place multiplicand, 3-place multiplier. Used by Keller for 
written, and by Thorndike for mental computation. 

O. Four-place multiplicand and multiplier. Used by Thorndike both 
for written, and for mental computation. The multiplicand was usually a 
combination of 6, 7, 8, and 9; the multiplier of 2, 3, 4, and 5. 



TEST 35: COMPUTATION 331 

p. Twenty-place multiplicand, 1-place multiplier. Used by Burgerstein, 
Laser, and Friedrich, with the restriction of the multiplier, in most tests, 
to 2, 3, 4, 5, or 6. 

Division 

Q. Three-place divisor, 7-place dividend. Four blanks of 10 problems 
each were used by Bellei for an hour's work. 

R. One-place divisor, 3-place dividend. Used by Kemsies for mental 
computation. 

There are certain advantages and certain disadvantages in each 
of these forms of material. In general, E must select that form of 
test that best suits the conditions under which he works. 

Materials. — Watch. Printed blanks, containing problems in 
addition or multiplication. 

Five forms have been prepared for this test : others may be prepared by 
E as desired. 

A. Addition test: several thousand digits in vertical columns with a line 
separating each 10 digits, after Model A. This form may be used with chil- 
dren or with adults, and either for short series or for continuous adding, after 
the Kraepelin method or after the plan of Krueger and Spearman. 

B. Addition test with 36 problems, patterned after Model G, but contain- 
ing 10, in place of 5 numbers each. 

C. Addition test, patterned after Model C (Schulze's method), and spe- 
cially recommended for younger S's. 

D. Addition test, patterned after Holmes, Model H, and virtually iden- 
tical with the material used by Burgerstein, Laser, and Friedrich. 

E. Multiplication test, after Model P, as used by Burgerstein, Laser, and 
Friedrich. 

Method. — For individual tests, Form B may be used with oral 
solution. Supply S with the printed test-sheet. Instruct him 
to call out the sums as rapidly as possible, but to correct any errors 
consciously made. Take his time for the solution of all the prob- 
lems, and, if desired, checkoff upon another sheet the point he has 
reached at every 10 or every 30 sec.^ This test has the advantage 
of freeing S from the labor of recording his results — a task which 
tends to introduce errors into the work of young, and to check the 
time of older S's. 

1 A refinement employed by Kraepelin enables E to record the time of 
every addition. >S writes the sums, using a pencil with electrical contacts 
(seeSchulze, 23: p. 250, or P. A., 2: 1899, 400), and a graphic record with time- 
control is arranged. 



332 ASSOCIATION, LEARNING, AND MEMORY 

Form A may be added orally by sections of 10 digits each. The 
other forms are less well adapted for oral solution, and, as the work 
is somewhat more difficult, it is not likely that S can compute 
faster than he can record his results. 

Reis' method may also be employed to advantage. 

For group tests, work by the time-limit method, selecting such 
a time that the fastest S in the group to be tested can no more than 
complete the task. 

If the group test is to be used with school children to determine 
efficiency under various conditions or at various times of the day, 
E must arrange the experiment to exclude, or at least to measure the 
influence of, all possible disturbing factors. The most serious 
of these are practise, excitement, ennui, and carelessness. 

A common method for cancelling out practise is to divide S's 
into two equivalent groups on the basis of a preliminary test, and 
to administer one set of problems early to the first, and late to the 
second group (if, for instance, fatigue is to be investigated), the 
other set late to the first, and early to the second group. 

In studying the work curve, some -E"s have used computation 
both as the test and as the work to induce fatigue, practise, etc.; 
others have used computation as a test of efficiency, but have al- 
lowed S to follow in the main the regular work of the school session. 
In the first procedure, computation (usually addition) is pursued 
more or less continuously for an hour, or even for several hours; in 
the second procedure, the computation itself occupies but a short 
time, relatively, say from 1 to 10 min., and is repeated at intervals 
of an hour or more, while S meantime takes up his regular tasks, 
indulges in physical activity, or rests, as E may direct. 

In illustration, Vogt, Oehrn, and other disciples of Kraepelin, have kept 
their S's adding continuously for several hours; Holmes used 4 periods of 
adding of 9 min. each, with 4-min. rest-pauses, Burgerstein 4 periods of 10 
min. each, with 5-min. pauses. Typical illustrations of the second pro- 
cedure are supplied by the investigations of Laser and of Ebbinghaus, who 
introduced 10-min. computation tests at the beginning of the school day 
and once an hour thereafter. Ebbinghaus is inclined, however, to recom- 
mend 5-min. tests as beina; cquotly serviceable for the determination of 
efficiency and less like'y to develop ennui and carelessness. OfTner (20. 
pp. 30-31) favors short tests for similar reasons and also for the partial avoid- 
ance of the practise-error. 



TEST 35: COMPUTATION 333 

Treatment of Data. — Computation tests yield two indexes of 
efficiency — speed or quantity of work and accuracy or quality 
of work. As a rule, no attempt has been made to unite these two 
indexes into a single index of net efficiency, although this might 
be done as explained in the Cancellation Test. Some ^'s, e.g., 
Oehrn, have considered speed of work only; others, e.g., Teljatnik, 
quality of work only. 

Quantity of work is indicated by elapsed time when using the 
incUvidual method, and by the number of problems solved (some- 
times by the number of figures written in the results) in the time- 
limit or group method. 

Quality of work is generally regarded as directly proportional 
to the percentage of correct solutions. Inaccuracy is most often 
taken in terms of the number of errors committed, less often in 
terms of the number of errors plus the number of corrections made 
by *S. The simplest, but the least desirable way to compute 
errors is to score one error for every wrong figure in the result. 
In the case of certain problems, however, a single error in computa- 
tion may affect more than one figure in the result.^ For reliable 
results, these complex errors must be examined and the score ad- 
justed to indicate exactly the number of real errors of computation. 

Results.- — (1) There are marked individual differences in the 
speed and accuracy of computation, even among S's of the same 
age and same school class. Schulze's best pupil added more than 
5 times as fast as the slowest pupil in the same class. Similar 
differences were discovered by Keller with school children and less 
striking differences by Oehrn with adults. 

(2) Where sex differences have been noted, the general evidence 
is in favor of a slight superiority of girls over hoys, e.g., in the re- 
sults of Miss Holmes. That the difference is but slight may be 
inferred from the conclusions of Fox and Thorndike (7) that the 
girls in the high school studied did about 5 per cent better on the 
whole than the boys, but this conclusion is offered with the reser- 
vation that a better grade of girls was probably selected by the 
school. Similarly, in combined ability with the opposites, alpha- 
bet, addition, multiplication, and word tests, as reported by 

' The problems in Form D (Example H) are intentionally arranged to 
reduce this error. 



334 ASSOCIATION, LEARNING, AND MEMORY 

Thorndike (26, p. 117), 48 per cent of the boys reached the degree 
of abiUty reached by 50 per cent of the girls. 

(3) PosUire was found by Jones (10) to affect the speed of add- 
ing; both children and college students could add somewhat faster 
(approximately 3 to 8 per cent) with the body in a horizontal than 
with tiic body in a vertical position. 

(4) The effect of distraction by concomitant activities, e.g., the 
reciting of a poem, was found by Vogt (29) to reduce very mate- 
rially (58.5 i)er cent) the number of additions made by the contin- 
uous (Kraepelin) method, but to have relatively little effect upon 
the simpler process of adding pairs of digits. 

(5) Practise increases the speed of computation, even when the 
test demands the exercise of associative connections in which S 
has already had extended school training. The interpretation 
of practise-effects in the analysis of the work curve is treated more 
fully below. 

(6) The results of investigations of the work curve may be 
most conveniently discussed under several distinct rubrics, since 
the conditions under which the tests have been applied appre- 
ciably affect their outcome. In particular, we may profitably ob- 
serve the distinction already drawn between investigations in 
which computation has served both as test and as work, and inves- 
tigations in which computation has served as test, but other forms 
of mental activity as work proper. The relation of individual dif- 
ferences to the general results of these investigations needs special 
consideration, as does also the effect of the insertion of rest-pauses. 

(rt) General analysis of the work curve. We have had occasion 
already^ to discuss the principal factors that condition the work 
curve. Extended accounts of these factors will be found in Meu- 
mann (18, II., 8 ff. and elsewhere), Schulze (23, 251 ff.), and Kraepe- 
lin (13, 14). The last-named investigator has been most active 
in this field, and to him we owe most of our information with re- 
gard to the part played by practise, fatigue, recuperation, adapta- 
tion (Gewohnwtg) , momentum or 'warming-up' (Anregung), and 
the various kinds of spurts (AtHriebe). In the experimental study 
of school children, still another factor, loss of interest, or ennui, and 

' See especially the Tapping and tlio Cancellation Tests, Nos. 10 and 26. 



TEST 35: COMPUTATION 335 

resultant carelessness, enters as a serious source of disturbance. 
It is clear that to determine the rise and development of any one 
of these factors, of fatigue for instance, the other factors must be 
eliminated or evaluated. 

(6) Individual differences in the work curve. We have noted the 
presence of clear-cut individual differences in the speed and accu- 
racy of computation; there are also individual differences in the 
course of the performance. Thus, both Kcmsics and Keller con- 
clude that mass results should be subjected to scrutiny to detect 
individual curves of performance, if reliable information is to be 
secured concerning fatigue and overpressure in the schools. 

Despite the great variety of individual work curves, they may be 
classified into a small number of characteristic patterns. Kemsies, 
for example, distinguishes between persistent workers who fatigue 
slowly and profit much by practise and feeble workers who fatigue 
quickly and do not profit much by practise. Meumann's own investi- 
gations lead him (18: vol. 2, pp. 10-11) to posit three types 
of workers (quantitatively regarded) : the first type attains maxi- 
mal efficiency at the start and thence decreases with many fluctua- 
tions : the second attains maximal efficiency only after an interval 
(of a length depending upon the kind of work) ; the third attains 
maximal efficiency only after a long period, i)erhaps several hours, 
of work. The first type, then, is characteriz(;d by rapid adapta- 
tion and rapid fatigue, the second by slower adaptation and slower 
fatigue, the third by very slow adaptation and very great resist- 
ance to fatigue. The third type is probably more common in 
adult males, the first in women and children. 

(c) The work curve for continued computation. 1. Work without 
interruption. Oehrn found that when adults added continuously 
Cor 2 hours or more, maximal speed was attained on the average 
at about 28 min. from the start. 

Schulze finds, however, that with school girls aged 12.5 yrs., 
signs of fatigue appear even in the first 5 min. The total number 
of additions made per minute by 37 girls was 1850, 1871, 1863, 
1785, and 1772 for the 1st to the 5th minute, respectively. 

Schulze's results with the same pupils for longer periods (50 
mill, without pause) show a progressive decrease both of quantity 
and of quality of work(Tal)le 54). These figures, which are selected 



336 



ASSOCIATION, LEARNING, AND MEMORY 



from the 6th of a series of experiments, are based upon the very 
easy process of adding two 1-placc digits. Practise has, therefore, 
i-ehitively httle effect, but fatigue diminishes efficiency. 

TABLE 54 

Ejliclency in Addiiiun: Five lO-Minuie Periods {Schulze) 







PERCENTAGE OF DE- 


PERCENTAGE OF DE- 


PKRIOn OFTEN 


TOTA.I. NUMBER OF 


CREASE OF QUANTITY 


CREASE OF QUALITY 


MINUTKS 


ADDITIONS 


OVER THE PREVIOUS 


OVER THE PREVIOUS 






PERIOD 


PERIOD 


I 


17,740 








II 


16,726 


5.7 


.09 


Ill 


15,85.-) 


5.2 


.03 


IV 


15,485 
15,134 


2.3 


.17 


\ 


2.3 


.01 



2. Work with interruptions. When repeated computation tests 
are made within an hour, the usual result is a progressive increase 
in the quantity, but a progressive decrease in the quality of the work. 
Burgerstein's figures (Table 55) furnish a typical example of the 
results for four lO-min. periods with 5 min. rest-intervals between 
j)(M-i()ds. 

TABLE 55 

Effiricnc!/ in Addilion and Multiplication within an Hour (Burgerstein) 



PERIOD 


NUMBER OF FIGURES 
IN RESULTS 

1 


NUMBER OF ERRORS 


PERCENTAGE OF 
ERROR 


I 


28,267 


851 


3.01 


II 


32,477 


1292 


3.98 


Ill 


35,443 


2011 


5.67 


IV 


39,450 


2360 


5,98 



Miss Holmes' results are similar, though, on account of comput- 
ing errors of a difTerent plan ('serial' errors counting but as one 
error), her percentage of error averaged but 1.3 as against Burger- 
stein's 3.^ 

' Miss Holmes' analysis of the errors showed that their increase during 
tlie hour was due primarily to increased inaccuracy in associative processes, 
rather than to increased frequency of 'slips of the pen.' In general, error.-^ 
of transcription were about one-third as numerous as errors of association. 



TEST 35: COMPUTATION 



337 



The general interpretation of results such as Burgerstein obtained has 
been that practise increases the speed of work, while fatigue increases its 
inaccuracy. Schulze's work with problems which were assumed to mini- 
mize the effect of practise may be regarded as corroborative of this view. 
On the other hand, Ebbinghaus (6, pp. 406-7) denies that practise could pro-- 
duce such marked increase of speed, and therefore ascribes both the increase 
in speed and the increase in inaccuracy primarily to progressively augment- 
ing haste and carelessness. 

(d) The work curve with short and scattered computation tests. Typ- 
ical instances of the use of computation as a test for the fatigue- 
effects of the regular school program are afforded by the experi- 
ments of Friedrich, of Laser, and of Ebbinghaus. This method has 
been adopted in part to avoid the entrance of ennui and careless- 
ness, as just mentioned. 

Laser's tests at hourly intervals of 226 pupils (aged 9-13 yrs.) 
in a Konigsberg Biirgerschule are summarized in Table 56. 
Inspection shows that, save for the 5th period, the outcome 
is the same as that of the tests for an hour's time by Burgerstein, 
viz: a progressive increase, both in speed and in inaccuracy of 
computation. 

TABLE 56 
in Computation within a School Session {Laser) 



TEST AFTER SCHOOL 
PERIOD 


TOTAL NUMBER OP 
FIGURES ADDED 


TOTAL NUMBER OF 
ERRORS 


PERCENTAGE OF 
ERROR 


I.... 


34,900 

40,661 
43,124 
43,999 
45,890 


1147 
1460 
1713 
1796 
1668 


3 28 


II 


3.59 


Ill 


3.79 


IV 


4.08 


V 


3 63 







Ebbinghaus, who sought to determine the desirability or unde- 
sirability of a 5-hour continuous school session in a Gymnasium 
and higher girl's school at Breslau, obtained results identical with 
those of Laser so far as the qualitative aspects are concerned, but 
differing somewhat as regards the quantitative aspects, more par- 
ticularly in that speed of computation reached a maximum at the 
close of the 2d school period, to remain thereafter almost constant 
or to fall off slightly toward the close of the session 



338 ASSOCIATION. LEAKNIXC, AND MEMORY 

(<?) The effect of pauses upon the work curve.^ Periods of rest 
exercise a generally favorable effect upon efficiency in computa- 
tion, especially upon the quality of work. 

That a pause of 5 niin. will favor the quantity of work clone with- 
in a 50-nun. period is shown by the data of Table 57, which are de- 
rived by Burgerstein from Schulze. 

TABLE 57 
A(hii(io»s per Pupil, with and withoul a Rcst-Paiisc {Bunjcrstcin-Schiilze) 

FIRST 25 MINUTES I REST-PAUSE SECOND 25 MINUTES 



First test 1007 nmin. 1088 

Second test llKi Nouo 1042 



Similar conclusions are reached by Kraepelin from his tests of 
adults (13, pp. 10-17). 

The extended tests maiie by Friedrich upon 51 ten-year old 
Volksschule pupils included both exercises in dictation and in com- 
putation (20-min. tests with addition and multiplication). His 
results for computation tests are sununarized in Table 58. Con- 
sultation of the original records will show a striking agreement 
between the data for dictation and those for computation. 

(/) Efficiency at different periods of the day. Friedrich's results 
lead him to advise lighter work in the afternoon session. Bellei 
(2) found that boys and girls aged 12 solved problems in division 
more slowly and less accurately in the afternoon than in the morn- 
ing. Marsh (17) tested but a few individuals, so that it is prob- 
ably unsafe to make inductions from his data, which seemed to in- 
dicate a greater efficiency in adding at noon than later in the day, 
and in multiplication at between 1.30 and 3 p.m. than at C or at 
10.30 p.m. With adults there are certainly marked individual dif- 
ferences in the diurnal ebb and flow of efficiency. Frequently 
quoted are the experiments conducted by'Thorndike (25) upon 

' For a full discussion of the experimental examination of rest-pauses in 
their relation to efficiency, consult Burgerstein and Netolitzkj^ (4, pp. 554- 
565). 



TEST .35: COMPUTATION 

TABLE 58 

Effect of Pauses- ujjon Computalion (Friedrich) 



339 



TEST 


TIME 


PAUSE 


ERRORS PER 
THOUSAND 


I 


. . Before 1st hour 





11.19 


II 


. . After 1st hour 


None 


16.38 


Ill 


..' After 2d hour 


8 min. after 1st hour 


19.54 


Ilia.... 


. .1 After 2d hour 


None 


20.26 


IV 


.. After 3d hour 


Two of 15 min. each after 1st 






1 


and 2d hours 


19.36 


IVa . . . 


. . After 3d hour 


One of 15 min. after 2d hour 


22.28 


lYb.... 


. . After 3d hour 


None 


22,76 


V 


. . Before 1st hour 





18.88 


VI 


. . After 1st hour 


None 


20.61 


VII 


. . After 2d hour 


15 min. after 1st hour 


21.04 


Vila ... 


. 1 After 2d hour 


None 


24.06 



adults und children at different times of the day, both when the *S's 
were fresh and well rested and when they reported feelings of wea- 
riness. The net conclusions drawn by this investigator are that 
"incompetence, mental, fatigue, does not come in regular propor- 
tion to the work done," that feelings of fatigue are not measures 
of mental inability, that disinclination to work does not signify 
inability to work. Thus, in schoolroom tests at Cleveland, Ohio, 
and Scranton, Pa., pupils tested late (between 10 and 40 min. be- 
fore school closed) did 99.3 per cent as much work and made 103.9 
per cent as many mistakes as did those tested early (10 to 40 min. 
after school opened). It may be disputed, however, whether this 
demonstration that pupils can work nearly as well at the end of 
school session as at its beginning is equivalent, as some writers have 
thought, to a demonstration that they should be expected to 
work as well at the later periods. 

A special study of fatigue in evening schools by Winch (28) leads 
him to the conclusion "that evening work is comparatively un- 
profitable and that a short time in class in the evening is sufficient, 
plus the labors of the day, to induce a low condition of mental 
energy." Illustrative results are given in Table .59. 



340 ASSOCIATION, LEAENING, AND MEMORY 

TABLE 59 

Effects of Fatigue on Arithmetical Work in Evening Schools (Winch) 





TEST 


GKOUP-A 


OBSERVERS 


GROtJP-B OBSERVERS 




1 Time 


Mean Score 


Time 


Mean Score 


I.. 
II.. 




8.30 
8.00 


302 
363 


8.30 
9.00 


320 
286 



(g) Efficiency on different days of the week. The work of Kem- 
sies seems to indicate that efficiency in school children is higher 
in the first than in the later days of the week. 

(h) Efficiency at different periods of the year. Bellei concludes 
that a poorer quality of work is done by school children in June 
than in January, because of the accumulated effect of a long period 
of school work. 

(7) Correlations. Aikins, Thorndike, and Hubbell compared 
efficiency in adding with efficiency in the other 'association' 
tests (misspelled words, cancellation of two letters, and opposites), 
and (by a special method of estimating the index) found the qual- 
ity of work in adding and quantity of work in associating cor- 
related to a degree of 50 per cent in 8th-grade, and 20 per centin 
5th-grade pupils, and net efficiency in adding and net efficiency 
in associating correlated to a degree of 48 per cent. On the other 
hand, the percentage of error in adding and in the other association 
tests exhibited no correlation or one of but slight degree. 

Thorndike's study of mental resemblances in twins (27) showed 
a much higher correlation of ability in computation between twins 
than between siblings; thus, twins aged 9-11 years revealed a cor- 
relation of 0.90 in adding, and 0.91 in multiplication, and twins 
aged 12-14 years a correlation of 0.54 in adding and 0.69 in multi- 
plication: taken collectively, the index of correlation amounted 
to 0.75 for the adding, and 0.84 for the multiplication test. 

Fox and Thorndike (7) found that ability to add correlated to a 
fairly high degree, 0.75, with ability to multiply, but only to a small 
degree, 0.20 to 0.44, with ability to solve fractions or to perform 
other arithmetical problems. They conclude that ''ability in 



TEST 35: COMPUTATION 341 

arithmetic is thus but an abstract name for a number of partially 
independent abilities." Similarly, Burris (5) found that school 
grades in algebra and in geometry, as recorded in 19 representative 
high schools, showed, for nearly 1000 pupils, a correlation of but 
0.45. 

Krueger and Spearman (15, pp. 77-78) found a correlation 
between adding and pitch discrimination of 0.83, and between 
adding and the Ebbinghaus completion test of 0.93. 

(8) In mental defectives, ability to compute has been investigated 
by Reis, who found the average performance less and the vari- 
ability greater in the work of paralytics and hebephreniacs than 
in normal individuals. 

(9) Relation of quality and quantity of work. In general, for a 
given *S, speed and accuracy of computation are related inversely, 
but this generalization suffers exceptions. Kemsies found that 
the period of fastest computation did not coincide with the period 
of most accurate computation, a result which is illustrated in sev- 
eral of our tables. In comparing individual results, he found, 
similarly, that those who worked most rapidly tended to work most 
inaccurately. 

(10) Qualitative analysis. Those who have used computation 
tests have not sought, as a rule, to examine the mental processes 
involved in them. Oehrn, however, calls attention to the fact 
that practise in adding (by the Kraepelin method) tends to induce 
quasi-automatic addition. This circumstance, taken in conjunc- 
tion with the relatively small correlations between different forms 
of computation themselves, and between them and other abilities, 
lends countenance to Well's objection (30) to accepting the com- 
putation test, without further qualification, as a measure of general 
mental efficiency. 

REFERENCES 

(1) H. Aikins, E. L. Thorndike and Elizabeth Hubbell, Correlations among 
perceptive and associative processes, in P. R., 9 : 1902, 374-382. 

(2) Bellei, Ulteriore contributo alio studio della fatiga mentale nei fan- 
ciulli, in Rivista sperim. di freniatria, 30: May, 1904. See summary by 
BinetinA. P.,11: (1904)1905,369. 

(3) L. Burgerstein, Die Arbeitskurve einer Schulstunde, in Z. S., 4: 1891, 
543-564, 607-627. Also published separately in German, and in condensed 
form in English as: The working curve of an hour. 



342 ASSOCIATION, LEARNING, AND MEMORY 

(4) L. Burgerstein and A. Netolitzky, Handbuch der Schulhygiene, 2d. 
ed., Jena, 1902. Pp. 997. 

(5) W. P. Burris, The correlations of the abilities involved in secondary- 
school work, in C. C, 11 : 1903, 16-28. 

(6) H. Ebbinghaus, Ueber eine neue Methode zur Prtif ung geistiger Fahig- 
keiten in ihre Anwendung bei Schulkindern, in Z. P., 13: 1897, 401-457. 

(7) W. S. Fox and E. L. Thorndike, The relationships between the differ- 
ent abilities involved in the study of arithmetic. Sex differences in arith- 
metical ability, in C. C, 11: Feb., 1903, 32-40. 

(8) J. Friedrich, Untersuchungeniiber die Einflusse der Arbeitsdauerund 
der Arbeitspausen auf die geistige Leistungsfahigkeit der Schulkinder, in 
Z. P., 13: 1897, 1-53. 

(9) Marion E. Holmes, The fatigue of a school hour, in Pd. S., 3: 1895, 
213-324. 

(10) E. E. Jones, The influence of bodily posture on mental activities, 
N. Y., 1907. Pp. 60. (Reprinted from Archives of ps3'chology, No. 6.) 

(11) R. Keller, Ueber den 40-Minutenunterrichtsbetrieb des Gymnasiums 
u. der Industrieschule in Winterthur, in I. M. S. H., 2: 1906, 298-330, especi- 
ally 307-318. 

(12) F. Kemsies, Arbeitshygiene der Schule auf Grund von Ermlidungs- 
messungen,inS. Z.,2: 1898. Pp.64. 

(13) E. Kraepelin, Ueber geistige Arbeit, 2d. ed., Jena, 1897. Pp. 29. 

(14) E. Kraepelin, Die Arbeitscurve, in Ph.S., 19: 1902, 459-507. 

(15 F. Krueger and C. Spearman, Die Korrelationzwischen verschiedenen 
geistigen Leistungsfiihigkeiten, in Z. P., 44: 1907 50-114. 

(16) H. Laser, Ueber geistige Ermiidung beim Schulunterrichte, in Z. S., 
7 : 1894, 2-22. 

(17) H. D. Marsh, The diurnal course of efSciency (Columbia Univ. the- 
sis), N. Y., 1906. Pp.99. 

(18) E. Meumann, Vorlesungen zur Einftihrung in die exp. Padagogik, 2 
vols., Leipzig, 1907. Pp. 555 and 467. 

(19) A. Oehrn, Exp. Studien zur Individualpsychologie, in P. A., 1 : 1896, 
92-151. 

(20) M. Oflfner, Die geistige Ermudung, Berlin, 1910. Pp. 88. 

(21) J. Reis, Ueber einfache psychologische Versuche an Gesunden u. 
Geisteskranken, in P. A., 2: 1899, 587-694. 

(22) R. Schulze, 500,000 Rechenaufgaben. Eine exp. Untersuchung, in 
Praktische Schulmann, 44: 1895, 340. 

(23) R. Schulze, Aus der Werkstatt der exp. Psychologic u. Padagogik, 
Leipzig, 1909. Pp. 292. 

(24) Teljatnik, article in Russian. See for details, Burgerstein u. Net- 
olitzky, 4: especially pp. 462-5. 

(25) E. L. Thorndike, Mental fatigue, in P. R., 7: 1900, 466-482, 547-579- 

(26) E. L. Thorndike, Educational psychology, N. Y., 1903. Pp. 177. 



TEST 36: MIRROR-DRAWING 343 

(27) E. L. Thorndike, Measurements of twins, in Archives of Phil., Psych, 
etc., No. 1, Sept., 1905. Pp. 64. 

(28) W. H. Winch, Some measurements of mental fatigue in adolescent 
pupils in evening schools, in J. E. P., 1 : 1901, 13-23, 83-100. 

(29) R. Vogt, Ueber Ablenkbarkeit u. Gewohnungsfjihigkeit, in P. A., 
3: 1901, 62-201, especially 80-118, 131-5. 

(30) F. L. Wells, Technical aspects of experimental psychopathology, in 
Amer. J. of Insanity, 64: January, 1908, 477-512. 

TEST 36 

Learning; Habit-formation in mirror-drawing. — The preced- 
ing tests of association deal with *S's facihty in producing unre- 
stricted series, or in reproducing restricted series that have already 
beeji learned. The present test compels S to form a new series 
of . associations that are opposed to associations stereotyped by 
several years of daily experience. 

More particularly, in tracing an ordinary drawing, the move- 
ments of the hand are guided by the visual perception of the draw- 
ing, plus kinesthetic sensations set up by the movement of the 
pencil. If the drawing is seen in a mirror, the natural relations are 
reversed in certain respects, so that a new series of associative con- 
nections must be established between eye and hand. The rapid- 
ity and ease with which these new connections are established is 
taken as an index of learning-capacity. 

Learning is often said to take place either by practise (trial and 
error), by imitation, or by some form of ideational control (in- 
struction, reasoning, etc.). In the mirror-drawing test, the condi- 
tions preclude the use of imitation, and there is but relatively little 
opportunity to employ ideational control; whatever improvement 
appears is due primarily to a process of trial and error. 

Mirror-drawing has been suggested by Judd (5, p. 99) to deter- 
mine the effect of practise in the acquisition of motor habits, by 
Starch (8) as a demonstration-experiment to illustrate the trial 
and error method of learning and the cross-transfer of practise, and 
by Burt (3) to measure adaptability^ and its correlation with gen- 
eral intelligence. 

1 For a discussion of prolonged adaptation to mirror-vision, see Stratton 
(9). 



344 ASSOCIATION, LEARNING, AND MEMORY 

Apparatus. — A 6-pointed star, printed in red ink.^ Mirror. 
Cardboard about 17 x 24 cm. [For the subsidiar}^ tests, a 20 deg. 
prism.] 

Preliminaries. — Pin the star out flat upon a table, directly in 
front of S, with the small cross-line that indicates the starting- 
point at the back, and the card square with the edge of the table. 
(This brings the star slightly 'out of true,' as is intended.) Set up 
the mirror, inclined slightly (about 5 deg.) from the vertical, just 
beyond the card. Arrange the screen (see Fig. 52) so that it will 
cut off S's direct view of the star, but will allow him to see it clearly 
in the mirror, and will not interfere with his hand in drawing. 

Method. — Place the point of a lead pencil upon the cross-line 
of the star, and assist S to grasp the pencil (permitting him to look 
only in the mirror). Instruct 5.- "Trace the outline of the star, 
starting in this direction [indicating, by pointing, the tip of the star 
at the right of the cross-line]. Work as rapidly as you can, but 
try to keep on the line. Don't stop to figure out what you ought 
to do, but keep your pencil going in some direction, and keep its 
point on the paper all the time." Start the watch, and record the 
time for the entire drawing. 

E may also note the time for each sixth of the pattern. But it 
is, perhaps, more desirable to supplement the total time by a record 
of the total number of corrective movements made by *S. Since 
these movements are often rapid, and of short extent, it is neces- 
sary to use a mechanical, or other form of counter to obtain the 
record. Press the counter every time S moves toward the line.^ 

1 This star resembles the pattern devised by W. F. Dearborn, and described 
by Starch, but it has been modified by being made slightly larger, printed in 
red ink, and tipped somewhat away from the vertical position, in order to 
avoid the too-easily drawn vertical lines. 

The author is experimenting with still another modification, viz : the use 
of double concentric stars, in the hope that this pattern may restrict the ex- 
tent of permissible excursion from the printed outline. With the single star, 
some >S's are inclined to slight their work, and so to reduce their time, while 
others try to keep exactly upon the line, with consequent extension of their 
time-records. Thus, one S, on his first trial, followed the tracing very poorly 
but completed his work in 46 sec. : on being asked to keep nearer the line, 
he consumed, on his second trial, 195 sec. 

- Every 'error,' or movement away from the line must, of course, be com- 
pensated for by a return movement. The idea is to register the number of 
these errors, or corrective movements. Changes of direction necessitated 
by the pattern itself are, obviously, to be neglected. 



TEST 36: MIRROR-DRAWING 



345 



For a standard test, make 5 trials with the right hand, using a 
fresh star for each trial. 

Variations of Method. — Make the first trial with the left 
hand : follow with a series of from 5 to 50 trials with the right hand: 
return to the left hand for a final test. Note how much practise 
effect has been 'transferred' from the one hand to the other. Plot 
a graph to show the effect of practise, both upon the time and 
upon the corrective movements. 




FIG. 52. THE MIRROR-DRAWING TEST. 

Treatment of Data. — In the standard form of test, £' has avail- 
able 5 records, in each of which he knows the total time and the 
number of corrective movements. S may then be compared with 
other aS's in respect to his performance in the first trial, or in all 
five trials, or in respect to the relative gain in the 5th as compared 
with the 1st trial, and, in each case, either total time or number of 
corrective movements may be made the basis of comparison.^ 



1 Other methods of treatment are suggested by Burt, who, however, con- 
cluded that the second of those we have mentioned (average or sum of speeds 
in all the trials) was most practical. 



346 ASSOCIATION, LEARNING, AND MEMORY 

Results. — (1) Individual differences in this test are manifest: 
the time for tracing the star at the first attempt varies, for adults 
at least, from about 50 sees, to over 8 min. 

(2) Sex. The author's tests, as well as those of Burt (by a some- 
what different method), indicate faster speed for women and girls 
than for men and boys. It is not only possible, but probable, that 
this difference is due in large measure to greater familiarity of wo- 
men with the use of the mirror, though Burt believes that it 
may be due in part, also, to an innate sex difference. Illustrative 
data are given in Table 60 : other tests with adults have revealed 
the following sex differences: 

Eleven men, average time 220 sec, average corrective move- 
ments 75. 

Eight women, average time 130 sec, average corrective move- 
ments 34. 

(3) (a) The effect of practise for a short series is shown in Table 
60, and for a series of 100 trials, one trial daily, in Fig. 53. 

TABLE 60 
Effect of Practise on Speed in Mirror-Draiving. College Students {Whipple) 





KrXTMBER 


1st 


1st 


2d 


3d 


4th 


5lH 


2d 




LEFT 


RIGHT 


RIGHT 


RIGHT 


RIGHT 


RIGHT 


LEFT 


Men 


11 1 


169 


127 


108 


96 


80 


67 


88 


Women . . . 


23 


149 


.27 


87 


76 


67 


'' 1 


74 



(6) In Starch's long period of practise, it will be noted that the 
improvement in speed and in accuracy (freedom from corrective 
movements) is not parallel, save for the first 7 or 8 days. Both 
speed and accuracy seem to have reached their limit of improve- 
ment at the 90th day. 

(c) Cross-education. A considerable amount of practise gained 
with the one hand is transferred to the other (unpractised) hand. 
Thus, Starch's 100-day practise with the right hand effected an 
improvement in it of 92 per cent in accuracy and of 84 per cent in 
speed. A single left-hand record, made at the expiration of this 
period, showed, in comparison with a single left-hand record made 
before practise began, an improvement of 85 per cent in speed and 
of 81 per cent in accuracy. There is, however, nothing surpris- 



TEST 36: MIRROR-DRAWING 



347 



ing in this so-called 'cross-education/ since the tracing of the star 
in the mirror depends primarily upon coordinations established in 
the central nervous system : in other words, the transfer is only an 
outwardly apparent transfer: in reality, the same factors are at 
work in the control of either hand. 

(d) Persistence of practise. The effect of even a short period of 
practise in mirror-drawing is very persistent. Thus, Burt admin- 
istered 6 tests in succession, during which the average speed fell 
from 103 to 39.5 sec. Twelve weeks later, two tests were given 




FIG. 53. THE EFFECT OF PRACTISE UPON MIRROR-DRAWING. (From Starch) 



in succession; the average speed developed was 34.5 sec. in the first, 
and 27.4 sec. in the second: in other words, the 7th test surpassed 
the 6th, made 12 weeks previously. 

The extent to which this persistence of practise-effect was shared 
by Burt's S's is indicated by the correlation 0.52 between their 
standing before, and their standing after the 12-week interval. 

(4) Relation of speed and accuracy. We have already noted that 
speed and accuracy (freedom from corrective movements) do not 
necessarily follow parallel courses as practise continues. Yet, in 



348 ASSOCIATION, LEARNING, AND MEMORY 

general, these two indexes of efficiency are closely correlated. The 
author's data for 19 cases indicate, for example, a correlation of 
0.86, P.E., 0.04, between total time and number of corrective 
movements. 

(5) Correlation with intelligence. The author could discern no 
constant differences between the work of 5 dull and 5 bright boys. 
Burt, however, found a correlation between speed and estimated 
intelligence of 0.67, P.E. 0.07, for elementary school boys, and of 
0.54, P.E. 0.14, for preparatory school boys. 

(6) Qualitative aspects. Efficiency in mirror-drawing may result 
from the actual formation of new visual-motor coordinations (in- 
deed, some *S's after executing a number of drawings, find that, for 
a short time immediately thereafter, these new coordinations inter- 
fere with normal drawing or writing); but efficiency may also 
result from the voluntary inhibition of visual control in favor of 
kinesthetic control, i.e., by thinking the drawing of a star in motor 
terms, as if working with the eyes shut. Or, the hand-movements 
may be started in this manner and then carried out by visual con- 
trol from the mirror. Finally, adults occasionally control the 
drawing ideationally, i. e., by applying inferred properties of re- 
flection by mirrors. 

It is evident that the existence of these qualitative differences 
may invalidate the test, in so far as the quantitative data for 
different *S's may 'measure' radically different mental processes. 

Very slow /S's get ' caught' at certain difficult points of the draw- 
ing, where they make a long series of futile attempts to start in the 
right direction. Here the normal visual-motor control is too per- 
sistent to be readilj' broken or ignored. 

Notes. — A further study of the associative connections involved 
in mirror-drawing may be made by the use of dot-tapping through 
a prism or of the various forms of mirror-wi'iting.^ 

' On mirror-writing, consult Abt, Allen, Downey, Laprade, Lochte, Weber, 
and Wegener. The most elaborate statistical study is that of Lochte, who 
examined 2S04 pupils in Berlin, and found, for children aged 6-7 j'ears, 13.2 
per cent of spontaneous left-hand mirror-writing in boys and 25.4 per cent 
in girls, but for children aged 13-14 years, only 0.7 per cent in boj-s and 35 
per cent in girls. The tendency toward this type of writing appears, there- 
fore, to decrease with age, and to be more evident in girls than in boys. 

The most elaborate qualitative analysis of the various 'controls' used iv 
writing is that of Miss Downey. 



TEST 36: MIRROR-DRAWING 349 

For the first test, let *S shut his left eye, and strike repeatedly 
with his right forefinger, at a mark on the wall or table-top, making 
about one stroke per second, after the manner prescribed in the 
test of precision of aiming (No. 11). After this rhythmic move- 
ment has become well established, and without interrupting it in 
the least, place suddenly before his eye a 20 deg. prism, with the 
base toward his nose. The mark is thereby apparently displaced 
some 10 cm. to the left. Count the number of strokes that S 
makes before he hits the mark again (with the prism kept before 
the eye). Similarly, count the number of strokes necessary to hit 
the mark again when the prism is removed. 

For the second test, try any or all of the following : 

(1) Close the eyes and write with both hands simultaneously. 
Cases will then appear, particularly in young children, of spon- 
taneous mirror-writing (writing which reads correctly when held 
before a mirror) with the left hand. If this appears, see if S can 
write normally with the left hand when his eyes are closed. 

(2) Show S a sample of mirror- writing. Explain its nature. 
Ask him to write in a similar manner, first with his left, then with 
his right hand. 

(3) Write with both hands simultaneously, but with the left 
intentionally in mirror-writing. 

(4) Read normal writing when seen only as reflected in a mirror. 

(5) Write normally while watching the writing in the mirror, 
i.e., with hand and paper hidden from direct observation, as in 
the star test. 

REFERENCES 

(1) G. Abt, L'ecriture en miroir, in A. P., 8: 1901 (1902), 221-225. 

(2) F.J. Allen, Mirror-writing, in Brain, 19: 1896,385-7. 

(3) C. Burt, Experimental tests of general intelligence, in B. J. P., 3: De- 
cember, 1909, 94-177, especially 145-9. 

(4) June E. Downey, Control processes in modified hand-writing : an 
experimental study, in P. R. M. S., 9 : April, 1908, No. 37. Pp. 158. 

(5) C. H. Judd, Laboratory manual of psychology, New York, 1907. 

(6) A. Laprade, Contributions a I'etude de l'ecriture en miroir. 1902. 

(7) Lochte, Beitragzur Kenntnis des.Vorkommens u. der Bedeutung der 
Spiegelschrift, in Arch. f. Psychiatrie u. Nervenkrankheiten, 28: 1896,379- 
410. 

(8) D. Starch. A demonstration of the trial and error method of learning, 
in P. B., 7: January, 1910, 20-23. 



350 ASSOCIATION, LEARNING, AND MEMORY 

(9) G. M. Stratton, The spatial harmony of touch and sight, in Mind, n.s. 
7: 1899, 492-505. 

(10) H. Weber, Spiegelschrift u. Lenksehrift, in Zeits. f. klin. Med., 27. 

(11) H. Wegener, Die Spiegelschrift, in Z. P. P., 1: 1899, 254-269. 

TEST 37 

Learning : Substitution. — This test is one of many that may be 
devised to measure the rapidity with which associations are formed 
by repetition. Here the associations consist in connections between 
a series of symbols and the nine digits, and are established grad- 
ually as the test proceeds. In theory, an S whose nervous system 
is plastic and retentive, who, in other words, is a quick learner, will 
make most rapid progress. The learning differs in type from that 
of the proceeding test, since here the conditions demand that audi- 
tory, visual, or auditory-visual connections be formed by sheer 
repetition, whereas there, visual-motor connections were formed 
by trial and error. 

The principle embodied in the test admits, as has just been said, 
of numerous variations in detail of application. The two forms 
here presented are themselves modifications of a test devised by 
W. F. Dearborn, and used for some time at the University of Wis- 
consin. 

A. STANDARD FORM FOR INDIVIDUAL PROCEDURE 

Materials. — Printed cardboard form, 3x7 in., containing 9 
circles. Each circle contains a digit (from 1 to 9) and a symbol 
(square, asterisk, etc.). Sheet of 10-ply cardboard, 7 x 14 in. 
Four strips of cardboard, each 1 in. wide and 14 in. long. Test- 
strips of heavy paper, 4.5 x 20 in., on each of which are printed 
forty 5-place series of symbols, together with forty 5-place blank 
squares. Stop-watch. 

Preliminaries. — Glue the 3x7 card of circles to the 7 x 14 card- 
board, at the bottom. Glue the narrow strips of cardboard, two 
strips thick, along either edge of the under surface of the same card- 
board, so as to form a 'tunnel' underneath the cardboard, through 
which the test-strips may slide. 

Method. — Lay the prepared cardboard fiat upon the table. 
Insert a test-strip, so that the first line of characters comes just 



TEST 37: SUBSTITUTION 351 

below the bottom edge of the cardboard, and hence just beneath 
the nine circles. 

Cover the test-material, and do not allow S to examine it (save 
as specified below) before the test. 

Give S the following explanation: "You will find on the table 
a sheet of cardboard, with nine circles at the bottom of it. In each 
circle you will find a number, running from 1 to 9, and a symbol, 
i. e., a small character or drawing. Then, you will find a strip of 
paper with rows of the same characters, and with empty squares 
beside them. What you are to do is to write in these empty 
squares the numbers that correspond with the characters. Keep 
at work continuously, as fast as you can, until you have filled in 
all the empty squares on the paper. Of course, you will have to 
look back and forth from the paper to the circles to find out what 
number to use, unless you can, after a while, remember some of 
the numbers without looking at them." 

With young *S's, this verbal explanation will be insufficient to 
make the task clear. It will do no harm, in such cases, to show S, 
for a brief instant, the card of circles, and a test-strip that has 
already been filled out. Let him see them just long enough to 
make the instructions clear, but not long enough to permit him to 
learn any of the associations. 

Start the watch when S starts the first line: keep the watch in 
view, but out of S's sight: record, without stopping the watch, the 
position of the second-hand when S completes every 5th line (in- 
dicated, for this purpose, by a heavier division-line in the test-strip.) 

As fast as S finishes a fine (or two lines), let him push the strip 
forward to bring a fresh line of symbols into position at the edge 
of the pattern (card of circles). 

When the 40th line is written, conceal the circles, immediately 
turn over the test-strip, write on it the digits 1 to 9, and ask S to 
place above each digit the character that accompanies it. As- 
certain, if possible, whether S relied upon visual, auditory, visual- 
auditory, or some other type of associative imagery. 

Treatment of Data. — Check up the test-strip for errors. Com- 
pare S's with respect to (1) their time for the whole test, (2) their 
gain in the last, as related to their speed in the first 5-line section, 
(3) their accuracy, and (4) their knowledge of the symbols (credit- 



352 ASSOCIATION, LEARNING, AND MEMORY 

ing'l for each symbol correctlj^ reproduced, and 1 for each paur of 
transposed symbols) . Plot graphs showing the variation in speed 
for the eight sections. 

B. FORM FOR GROUP TESTS, OR FOR SUPPLEMENTARY INDIVIDUAL 
TESTS 

Materials. — Printed form, at the top of wliich are shown 9 
circles, as in Form A (save that different symbols are used), and in 
the body of which is provided, in two columns, a series of forty 
5-place numbers and forty 5-place blank squares in which the 
appropriate symbols are to be placed. Stop-watch. 

Method. — For individual tests, give instructions similar to 
those for Form A, with such modifications as the altered arrange- 
ment of the material necessitates. Make clear, especially, that 
the second colunm is to be filled out the moment that the first 
is completed. 

For group tests, supplement the instructions by an adequate 
blackboard explanation, preferably with an illustration so devised 
as not to give information concerning the symbols to be used. 
Have the papers distributed, face down, to be turned over only at 
the command to start. Work by the time-limit method, allow- 
ing 4 min. for the test. Instruct <S's to place an oblique mark at 
the point reached when the command "mark" is heard. Give this 
signal every 30 sec, so that the work is divided into 8 periods of 30 
sec. each. Conclude with the symbol-test as in the individual 
method. Plot curves for 30 sec. intervals. 

Variations OF Method. — Cut off the top of the paper: glue 
the pattern of circles on a sheet of cardboard, as in Form A. Cut 
and paste the two test-columns to form a single long column, as 
in Form A. This will }iermit check-tests, comparable with the 
standard method, save that here sjanbols, there digits are written. 

Repeat either Form A or Form B after an interval of several 
hours, days, or weeks, to compare the permanence, in different 
S's, of the associative connections established in a single trial. 

Repeat Form A until the associations are firmly established, and 
the digits can be written rapidly without seeing the pattern. As- 
certain whether the use of Form B will then develop interference 
of associations. 



TEST 37: SUBSTITUTION 



353 



Results. — (1) Individual differences are easily demonstrated. 
Thus, in a 4-min. test of 40 college students, in the same class 
(Table 61), the fastest S wrote 53 per cent more symbols than the 
slowest *S, and in individual tests of 18 students and college in- 
structors (Table 62), the fastest S finished in 44 per cent quicker 
time than the slowest *S'. 

(2) Sex differences are less evident than in the mirror-drawing 
test of learning, but the evidence so far adduced is in favor of an 
appreciable superiority of women (Tables 61 and 62). The fastest 



Substilution Test. 



THIRTY SBC. PERIOD 



Number of Symbols Written. 
(Whipple) 



2d 3d i 4th 



Form B. Group Method 



7th 8th total 



Average, 12 men. 1.3. 7II6.I 14.6 16. .s' 14.8 17.2 16.7 17.9 127.3 8 

Average,28womenil3.9J15.4 16.0; 17.9} 16. 0' 17.0 16.8 19.0! 132.0 8.2 

Fastest individual 10. 21.0 22. 0| 18.0 23.0 20.0 25.0 26.0 16.5.0 9 

.Slowest individualill. 013.0 8.0; 10.0 12.0 10.0 11.0 13.0 95.0 3 



TABLE 62 
Substitution Test. Speed in Seconds . FormB. Individual Method (Whipple) 



SECTION OF 5 LINES 



3d i 


4th 


5th 


6th 


1 

45.8 


44.8 


46.1 


44.4 


40.6 


.38.6 


43.4 


37.6 


44.3 


43.1 


45.4 


42.5 


33,0 


30.0 


36.0 


29.0 


59.0 


fil 


62.0 


.53.0 



7th 8th TOTAL 



Average, 13 men 54.0 46.0 



Average, 5 women. 

Total. 18 cases 

Fastest individual . 
Slow(!st individual. 



45.8 41.2 
51.8 44.7 



42.0 
63.0 



35.0 
58.0 



47.7, 44.3 353.1 

36.61 35.0 318.8 

44.6 41.7 358.1 

31.0 .34.0 270.0 

GOO 65 481 



>S' in each group tested was a woman, the slowest ri in each group 
was a man. 

(3) The effect of age upon the outcome of the substitution test 
may be roughly estimated by comparing the averages for adults, 
in Tables 61 and 62, with the averages for grammar-school boys, 
in Table 63. 

(4) A tendency toward a correlation with intelligence is indicated 
by the comparison of 6 dull, and 5 bright grammar-school boys 



354 



ASSOCIATION, LEARNING, AND MEMORY 



(Tabic 63). All the bright boys, with a single exception, are 
younger than the dull boys, yet they show unquestioned superi- 
ority. 

(5) Improveinent curve, (a) Comparison of the 8 sections into 
which the test has been divided shows that, in general, the forma- 
tion of associative connections brings about a progressive increase 
in speed of work, amounting, roughly, to from 10 to 20 per cent, 
when the first is compared with the last section. 



Substitulion Test. BrUjht and Dull Boys. Form B. Individual Method 
(Whipple) 



AOE SCHOOI. GRADE TIME IN SEC. STMBOL SCORE 



Dull 
Group 



H. 


16:9 


7, II 


700 


K. 


13:1 


5, II 


742 


N. 


14:9 


6, I 


422 


M. 


12:8 


6, I 


975 


B. 


12:6 


7, II 


707 


S. 


15:2 


6,1 


660 



Average 



14:2 



701 



6.17 





lir. 


11:11 


S, I 


677 


9 




llu. 


12 :S 


6, II 


597 


5 


Bright 


Id. 


10:9 


(i. 11 


566 


9 


Group 


Tr. 


10:4 


6, II 


648 


4 




Fe. 


10:8 


6,11 


591 


9 


Average ... 




11:1 




615.8 


7.2 



ib) This increase of speed is, however, not uniform. In par- 
ticular, a tendency may be discovered, e.g., in Tables 61 and 62, 
toward a decrease of efficiency at about the middle of the work. 
Thus, in the individual tests, both men and women, taken col- 
lectively, exhibit a reduction of speed in the 5th section, while in 
the group tests, both men and women Avrite fewer symbols in the 
5th, than in the 4th 30-sec. period. 



TEST 37: SUBSTITUTION 



355 



In the individual tests, the 4th section comes at the bottom of the first 
column, the 5th at the top of the second column. The brief delay occasioned 
by the necessary readjustment (of paper, pencil, attention, etc.) may ex- 
plain a part, but only a part of the reduction in time. 

A plausible explanation is that reported by one >S,who noted that, in Sec- 
tion 4, being so far from the circles, she relied upon her memory, where- 
in Section 5, the very proximity of the circles tempted her to glance at 
them to make sure of her work, and thus to work more slowly. ^ 

To test this hypothesis, trials were made with 10 college students, using 
material of Form B, but rearranged (as suggested above) to resemble 
Form A (the test-blank in one long column sliding beneath the cardboard). 
The average scores, in sec, per o-line section, were 55.7, 48.6, 44.0, 40.9, 4^.0, 
40.3, 41.5, and 40.8, for the sections 1 to 8, respectively. (Total time, 354.8 
sec; symbol score, 8.2). There is, then, still a loss of more than 2 sec at 
Section 5. 

It would appear, therefore, either that the test-material of Section 5 hap- 
pens to be more difficult than that of Sections 4 and 6, or that, as a final 
possibility, the slower rate in Section 5 is merely an expression of a mental 
condition — fatigue, weariness, loss of initial enthusiasm. That this explan- 
ation may be entertained is shown in Table 64, where it will be seen that, 
although more »S's lose speed in the 5th, than in any other section, there are, 
nevertheless, numerous instances of loss of speed in other portions of the 
work, especially in Section 7. The S's of Table 64 are the 10 just mentioned, 
and the 18 of Table 62. 



TABLE 64 
Substitution Test. Distribution of Gains and Losses in Speed (Whipple) 



SECTIONS 


1-2 


i ■ 1 

2-3 ' 3-4 4-5 5-6 


- r 

6-7 7-"^ 


Number gaining speed 

Number losing speed 

Number maintaining speed. . . 


24 
4 



17 16 9 19 

7 8 16 8 

4 1 4 3 1 1 


12 16 

15 8 

1 4 



(6) S's who make the fastest records commonly employ the 
scheme of holding in mind the entire 5-place number (in Form B), 
and writing down the symbols while keeping the eyes directed 
upon the circles. The material in Form A lends itself less easily 
to this scheme. 



'Form A has been devised especially to avoid the variation in distance of 
test-blanks from the pattern at difi"erent periods of the work. 



o50 ASSOCIATION. LEAKNINtl, ANO MKAUUn 

TEST 38 

Memory for serial impressions: 'Rote' memory.' Tlio 
essential idea of the several forms of memory test treated under this 
title is to present a series of discrete impressions, e.g., letters, 
digits, words, which is, if possible, to be reproduced in correct 
order and exactly as presented. These tests are to be contrasted 
Math the so-called tests of 'logical' men\ory, in which the material 
presented is a logically connected whok\ and in Avhich the require- 
ment is to reproduce the substance, or tlie meaning, of what has 
been presented. In either test, the reproduction may be inunediate 
or delayed, and the mode of presentation and nu^thod of measuring 
elHciency may be varied in many ways. 

Memory for a series of discrete impressions has been used to 
study individual ditferences, as conditioned by sex, age, mental 
ability, to detect fatigue, to investigate the nature of practise, 
the possibility of training retention and recall, the most ect^iomical 
methods of learning, etc. 

To understand the results and conclusions of the small army of 
investigators of memory, it is convenient to classify the methods 
and the materials that have been most commonly used.- 

OLASSIFICATION OF INIKTUODS FOR MF.MOKV TKS'rs 

(1) The method of complete memorization, or method of complete 
mastery (Erlernungsmethode), developed in the classic work of 
Ebbingliaus {Ucbcr das GeddcJitnis) in 1885, and refined by Mid- 
ler and Schumann, demands that ^' repeat the series of im- 
pressions again and again until he can reproduce it without error, 
without hesitation, and with certainty of correctness. Efhciency 
is measured by the number of pres(>utations riHiuircnl for this com- 
plete learning. 

*Thc author desires to acknowledge the assislaiice of Dr. li. Iv. (ieissler, 
of Cornell University, in the collation and sifting of tlie literal ure hearing 
upon this test. 

aFor more extendetl discussion of the historical developineni of t he sev- 
eral experimental methods, together with accounts of the results (hat have 
been attained, the reader should consult Bentlev (1). Binet(()), Hurnham(ll), 
Ehhinghaus (I5b), Gamble (10), Henri (21), OITner (;i7), and Pohliuanu (38). 
The last-named gives a i>articularty valuable summary of (he met Hods. 



TEST 38: ROTE MEMORY 357 

In practise, this method is frequently supplemented by testing 
the number of presentations of the same series that is needed to 
relearn it at any assigned time after the first learning (Ersparnis- 
verfahren or Ersparnismethode) , in which case the saving in num- 
ber of repetitions in tlie relearning, as compared with the learning, 
measures the amount of retention, or the degree to which the first 
impression has persisted. 

(2) The memory span method (Methode der Geddchtnis-S panne) , 
first devised by Jacobs (22), elaborated by Ebert and Meumann, 
and extensively used in England and America, consists in the 
determination of the maximal length of a series of impressions that 
can be reproduced with a given degree of accuracy (usually com- 
plete accuracy) after a given number of repetitions (usually, 
though not necessarily, one repetition) . Ordinarily, E begins with 
a series that is easily within *S's limit, and increases the length of 
the series, keeping other factors constant, until errors appear. 

(3) The method of retained members (Methode der behaltenen 
Glieder), first so designated by Ebbinghaus, but more carefully 
studied by Pohlmann, consists in the determination of the degree 
of mastery (proportion of elements correctly reproduced) of a 
series of a given length, after a given number of repetitions. The 
method is somewhat like the span method, but the length of the 
series is so chosen that *S' cannot attain complete mastery. In 
practise, many span tests actually become tests of degree of mas- 
tery. 

(4) The method of right associates (Treffermelhode) , proposed by 
Jost (24), and developed by Miiller and Pilzecker (33), consists 
in presenting a series of impressions (typically, nonsense syllables 
in trochaic rhythm), and of subsequently testing *S"s ability to 
name the member that follows any given member. Usually the 
accented member is given, and S tries to designate the ' right asso- 
ciate' for it. (When his time of response is measured, the method 
is known, in full, as the Treffer- und Zeitmethode) . Its special 
value is to afford opportunity for analyzing the nature of the 
associative connections, and it has not been proposed as a test of 
efficiency. 

(5) The method of prompting {Methode der Hilfen), somewhat 
similarly, tests the nature and strength of the individual associa- 



358 ASSOCIATION, LKAKNING, AND MKMDKY 

ti\o connections in the series, and is of questionable usefulness for 
practical testing. As illustrated in the work of Ephrussi (17), 
the method consists in an attempt by ^I to reproduce the series 
before it has been fully learned, and in prt)mpting;s by E at each 
point of hesitation or error. Efficiency is inversely related to the 
number of promptings required. 

(6) The method of interference of assoeiations is exempliticd in 
Bergstrom's study of card-sorting (2): here 80 cards are sorted by 
E into 10 piles, and subsequently, at a givi^u interval, into another 
10 ])iles ditTerently arranged; the second sorting is slower because 
of the persistence of associative connections developed in the 
first trial. Analogous tests can be fashioned with other forms of 
material, as has been suggested in the Substitution Test . 

(7) The ntethod of reconstruction, used by JNIiinsterberg and 
Bigham with colors, and by IMiss Gamble with odors (19), consists 
in presenting a series of stimuli in a definite order, and then, after 
a predetermined interval, in presenting the same stimuli in chance 
order. <S attempts to rearrange them in the original order. 

(8) The incthod of recognition consists in the i)resentation of ji 
limited number of impressions, which are subsequently presented 
again, in conjunction with other stimuli, to see how many of the 
first series *S can recognize in the second series. Examples will be 
found in the works of Smith and of Henri. 

(9) The method of identicol series, as employi>d by iunithcr (,39), 
is a modification of the method of recognition, in Avhicli the original 
series is always actually presented intact, though, of course, this 
fact is concealed from *S. 

(10) The method of continuous lists {Methode desfortlaufenden 
Niederschreihens oder Aufzdhlens), emploj-ed by Krtepelin (27), is 
identical with the procedure described in Test 33, though sometimes 
S is required to write words that belong to specified categories. 

(11) The method of chance verbal reactions {Methode der zu- 
fdlligen Wortreactionen), well illustrated by the investigations of 
AschatTenburg and O. E. Miiller, is the stock association experi- 
ment, witii emphasis upon the qualitati\e as well as the quantita- 
tive study of the associative sequences. 

(12) The method of deseript ion or report [Aussage) is a form of 
memorv investigation with peculiar ])r()blenis o( its mvn, as has 



TEST 38: ROTP] MEMORY 359 

been shown in Test 32. In it, the terms in which the reproduction 
takes place are not restricted to a direct equivalence with the 
material presented, but are merely indicative or descriptive of this 
material. 

CLASSIFICATION OF MATERIAL FOR MEMORY TESTS 

The material used in tests of serial memory may be classed 
according to the sense-department to which it is presented (visual, 
auditory, visual-auditory, etc.), and according to its nature or 
form. Again, visual material of different forms may be presented 
either simultaneously or successively. 

(1) Actual objects were used by Netschajeff (35), Lobsien (30) and Kirk- 
patrick (26). Thus, Lobsien showed 9 objects at the rate of 1 per sec, e.g., 
newspaper, key, handkerchief, glass, slate, box, book, glove, chalk. Netscha- 
jeff used 12, Kirkpatrick 10 objects. 

(2) Pictures of objects, 10 in number, were used by Miss Calkins (13). 

(3) Sentences were used by Ritter (40), Miss Sharp (42), and Binet. In 
general they prove unsatisfactory: it is difficult to secure series that are 
equivalent in length, construction, difficulty, and interest. A graded test 
series will, however, be found in connection with the Binet-Simon tests of 
Chapter XIII. 

(4) Words may be used in the most varied kinds of series. Thus, series 
of Latin-German, or English-German, or other pairs of nouns, have been 
used to produce a 'vocabulary' form of test, as by Wessely (49). A distinc- 
tion may be made between 'related' or 'associable' terms and 'unrelated' 
or 'dissociable' terms (Norsworthy, 36: Bergstrom, 3). For example, 
paper, writing, compose, etc., vs. horse, bricks, soldier, acorns, etc. Meumann 
(31) and Burt (12) have compared the span (3to8-term series) for concrete 
nouns, e.g., stove, ink, lamp, street, etc., with the span for abstract nouns, 
e.g., humanity, arrangement, organism, influence, etc. Netschajeff and Lob- 
sien tested the relative reproducibility of words (12 and 9-term series) that 
connoted visual, auditory, tactual, and emotional ideas, respectively. 
(Examples: lightning, dial, sunbeam: thunder, crash, whistle: cold, 
soft, smooth: hope, doubt, regret.) Kirkpatrick and Calkins also used 10- 
terrn series of words that related to objects, as did Pohlmann. Hawkins 
(20) compared simultaneous and successive exposure of 15 nouns. Binet, 
Ritter (40) and Sharp also employed lists of words of varied length and com- 
plexity. 

(5) Nonsense .syllables were tried but discarded by Jacobs. They formed, 
however, the stock material in Ebbinghaus' pioneer work, and were sub- 
sequently made more serviceable by the precise rules that Miiller and Schu- 



360 ASSOCIATION, LEARNING, AND MEMORY 

mann (34) formulated for their construction. Bergstrom, Burt, Smith, 
MiiUer and Pilzecker (33), Pohlmann (38), van Biervliet (48), and others 
have found them of value: indeed, Pohlmann contends that, on account of 
their equivalence one to another and their relative freedom from varying 
associations in different *S's, nonsense syllables form the best and most 
reliable material for memory tests. Series specially adapted for English 
readers will be found in Test 25. 

(6) Letters (usually consonants only, to avoid the formation of syllables 
or words) have been used by Jacobs, Binet (5), Cohn (14), Pohlmann, Sharp 
(42), Smith (44, 46), and Winch (50). An idea of the great variety of proce- 
dure that may be developed with a single form of material may be gained by 
noting that Binet used 15 consonants exposed visually and simultaneously, 
for 20 sec. ; Cohn exposed 12 consonants arranged in the form of a square for 
25 sec. ; Pohlmann read 10 consonants to his *S"s 3 times over; Sharp exposed 
12 letters successively with the Jastrow drop-apparatus, at the rate of 1 per 
sec, and repeated until the series was learned; Smith exposed 12 consonants 
simultaneously for 10 sec, and read other series of 4, 5, 6, 7, and 9-term 
consonants; Winch repeated 12 consonants auditorily in 25 sec, and also 
exposed 12 simultaneously for 25 sec. 

(7) Two-place numbers, administered orally, were used by Schuyten (8 
numbers repeated by S's in concert), Lobsien (9 numbers), Pohlmann (10 
numbers, given three times), and Netschajeff (12 numbers). 

(8) Digits,^ i.e., one-place numbers, have been employed by Jacobs, 
Johnson (23), Bolton (9), Binet, Ebbinghaus (15a), Hawkins (20), Ritter, 
Sharp, Smedley (43), Krueger and Spearman (28), Wissler (52), and many 
others, in the most varied manner (4 to 10-place series, given auditorily, 
visually — either simultaneously or successively — or in combined appeal to 
vision and audition, to vision, audition, and 'hand' memory, or to vision, 
audition, and 'articulatory' memory). 

(9) Geometrical draxoings have been used by Miinsterberg and Bigham, 
and by Bernstein and Bogdanoff (4), the latter selecting forms that would be 
unfamiliar to their S's. 

(10) Lines of varied lengths have been employed by Toulouse and by 
Binet (6). 

(11) Miscellaneous visual characters, symbols, combinations of dots, lines, 
etc., formed a portion of the material in the investigation of Ebert and Meu- 
mann. 



1 Reuther (39) has formulated rules for the construction of test-series of 
digits, analogous to the rules of Miiller and Schumann for test-series of 
nonsense syllables. The following are the most important of Reuther's 
principles: (1) Do not repeat a digit in the same series (impossible to avoid, 
of course, in 10-place series). (2) Do not begin a series with the number 1. 
(3) Avoid the use of zero. (4) Do not place any two digits in their natural 
relations with one another. (5) Do not use sequences that suggest historical 
dates. (6) Do not use in immediate succession two series that have the 
same digit in the same place at any point in the series. 



TEST 38: ROTE MEMORY 361 

(12) Sounds, such as those produced by tearing paper, whistling, stamp- 
ing, ringing a bell, etc., were arranged in 9-element series by Lobsien, and 
in 12-element series by Netschajeff. 

Aside from these wide differences in general method and in form of mate- 
rial, attention should be called to differences in rate or tempo at which the 
series is first presented, to differences in the number of times the series is 
presented, and to differences in the time-interval elapsing between presen- 
tation and reproduction. 

As a rule, the rate of presentation has been not slower than 1 impression 
in 2 sec, and not faster than 2 impressions in 1 sec. A rate of 1 impression 
in 0.75 sec. has been found well adapted for adults. 

The typical span test is one in which the series is presented but once: 
from the point of view of functional testing, therefore, the repetition of 
the stimulus series may be regarded as a variant method, not to be intro- 
duced save for the special purpose of studying its effect. 

Similarly, the greater portion of the tests here reported have been made 
with no interval between presentation and reproduction. It is to be noted, 
however, that Smedley, in his tests of Chicago school children, separated 
presentation and reproduction by an interval of 5 sec. Kirkpatrick, and 
Calkins in her repetition of his tests, secured a reproduction both immedi- 
ately after, and 3 days after the presentation, in order to contrast 'immedi- 
ate' with ' delayed' memory or recall. Somewhat similarly, Binet, and Sharp 
in her repetition of his tests, secured a reproduction of each of seven 7- 
place word-lists directly after its presentation, and a 'recapitulation,' 
in so far as it was possible, of the 49 terms at the close of the whole test, 
i.e., about 3 min. after the first presentation. Binet contrasts, in this way, 
immediate memory with what he terms 'memory of conservation.' 

Since, as the results that follow show, even minor variations in the con- 
duct of a memory test affect its outcome, it follows that the results of dif- 
ferent investigators may not be expected to exhibit complete accordance with 
respect to the relative influence of sex, age, mental ability, etc. 

Three chief forms of test have been selected and are recommended 
as standard for this field of investigation: variant methods are 
suggested in each case; but, by reference to the classification of 
methods and materials just given, E can devise further modifica- 
tions to suit special requirements. These three forms are (1) 
tests with digits, resembling in scope Smedley's Chicago tests, but 
with several differences in procedure, (2) tests with letters, after 
Cohn's method, and (3) tests with lists of words, after the methods 
of Meumann and of Burt. 



362 ASSOl'lA l'\()N, l.i:AKM\(i, AiNO MKMOKV 

A. IMMKDIATK MEMORY TESTS WITH DIGITS 

jMaterials.- Printed tost-canls, 42 in number, arrantied in 
three sets of 14 eards eai'li, iov presentation by 3 differiMit methods. 
Each sot contains 2 cards each o( 4, a, 0, 7, S, 0, anil 10 digits. 
]\Ietronomo (Fig. 14). [For serial visual exposure, in addition, 
Jastrow's memory apparatus (^Fig. 54). C'ardboanl. Willson's 
gummed figures, black. Size 5. For letter tests, full sets of gmnmed 
letters. Sizes 5 and 10.] 

Pheliminaries. — On the back of each card, write the digits that 
are printed on its face: this enables E, when the test demands it, 
to pronounce the test numbers while displaying the card to /S. 
The purely auditory and the auditory-visual-hand-motor series 
are not included in the printeil cards, but should be prepared by 
E, preferably, for convenience, on a single piece of cardboaril, the 
size of the printed cards. For the auditory- series, use the following 
numbers, in the order given: G13o, 2947, 30814. 57290, 241037, 
935810, 8537142. 9412837. 47293815, 71830245. 924738015. 
47529031S, 8097132504, 2140073859. For the visual-auditory- 
luunl-motor series, use these numbers, reversed, e.g., 531t), etc. 

^Method.— If only a single test can be made, employ the visual- 
auilitory-articulatory form of presentation, since this is most 
likely to produce uniform conditions of ideational imagery for all 
/S's. But if the tests can be taken in full, folknv the order of presen- 
tation outlined herewith.^ In any event, preface each form of 
presentation with a special, short sample-series, without demanding 
reproduction, in order that »S may be perfectly clear as to the nature 
of the test. Within ivich form of test, also, preface each presenta- 
tion with a statement of tlu> nunil>ei- of members in the coming 
series, e.g.: ''This will be a s(>ries of 5 digits." The metronome 
should be set at Ot), i.e.. one stroke per sih-.. for all tests.- 

' It goes without explantxt ion tl\at the longer series may be omitted with 
very young, tlie shorter witli mature <S's. Use, for the shortest series, one 
that is easily witliiu tlio span of tlio poorest 8 (o l>e testect, for tlie longest 
series, one tluit is tooditMciilt for tlie host N to reproduce witliout error. 

^ It may lie well at this jilaoe to point out tlie ditTorences between this 
procedure and tliat followeit by Siuedley at (.'liicago. Snu^iley used no 
series longer than S. He gave no warning of tlie length of the coming series. 
He set the metrononu^ at !>0. He did not present the several series in regular 
order, but irregularly, though beginning with an easy series. He inserted 
an interval of 5 see. between presentation and reproduction. He distributed 



TEST 38: IIOTE MEMOItY 363 

(1) Auditory presentation. Explain the test by a simple illus- 
trative series. Require >S' to close his lips firmly, and to press his 
tongue against the roof of his mouth — this to reduce the tendency 
to articulation, and in group tests (all of the memory tests lend 
themselves well to group presentation) to avert communication 
between *S"s. Start the metronome.^ Pronounce the digits, one 
at a time, with the utmost care to ensure even tempo, clear articu- 
lation, and entire absence of rhythm.^ Directly at the conclu- 
sion of the series, let ;S' repeat as much as possible of it. Although, 
under some circumstances (with very young or backward >S"s), 
an oral reproduction may be imperative, a written rtjproduction 
sliould be considered standard, both because the proper placing 
of the digits furnishes E with data for scoring /S"s performance 
(and the placing must indicate possible omissions), and because 
experiment shows that, at least for maturer *S"s, written repro- 
duction is preferred, and is more successful than oral reproduction. 
S'h recall should, therefore, be entered upon a prepared blank, with 
the caution to indicate every omission by a dash or a blank space.' 

(2) Visual presentation. Use Cards V-4a, V-4b, etc. to V-lOb. 
Follow the directions for auditory presentation, but in place of 

his tests, seven in all, at hourly intervals. Finally, he gives no clear 
statement of his method of computing results, save that the "percentage 
correctly recorded constituted the grade," 

' If ho finds it necessary, J'J may substitute a silent metronome, made by 
swinging a small weight on a string, but the fact that the regular metronome 
is somewhat noisy should not be taken as evidence that it disturbs S: on 
the contrary, a noise of moderate intensity is not infrequently found to be 
a stimulus to better attention. Moreover, the ticking metronome is much 
more serviceable when S is asked to pronounce the digits in conjunction 
with E. 

' The difficulty of speaking without accent, or without grouping the digits^ 
has led Binet to reject oral, in favor of visual presentation. Even if E 
pronounces without accent or rhythm, there is no guarantee that S may not 
mentally cast the digits into a strongly accented and grouped series, and 
in fact, mature *S"s, working with the longer series, are almost certain to 
catch this 'trick' in time. Ritter (40) advocates that E should give a 
decided objective rhythm to every series on just this account: this factor 
will then form a constant, rather than a variable 'error.' One difficulty 
with this plan lies in the fact that, in using series of varying lengths, it is 
impossible to use any con.stant metrical phrasing. 

^ For group work, the class should be provided with blank forms, so num- 
bered and arranged that no misunderstandings may occur on the part of 
S in entering the data, or on the part of E in interpreting it. Allow ample 
time for writing: NetschajefT, Pohlmann and Schuyten all found 2 min. 
desirable in classroom tests. In group tests, care must be taken to prevent 
audible repetition of the digits during the reproduction. 



3G4 ASSOCIATION, LEARNING AND MEMORY 

pronunciation, exhibit the entire card for a length of time identical 
with that for auditory presentation, i. e., allowing 1 sec. per digit.^ 
Note to what extent S articulates the digits : even with lips and 
tongue placed as directed, they will often be seen to move, and 
contractions of throat muscles may also indicate partial articula- 
tion. 

(3) Auditory-visual 'presentation. E presents the cards, as in 
the purely visual procedure, but also pronounces the digits, as in 
the auditory procedure, by reading them from the back of the card. 
S sees and hears the digits. Cards AV-4a to AV-lOb are used. 

(4) Auditory-visual-articulatory presentation. E presents the 
cards as in (2) . E and S pronounce them in concert, in time with 
the metronome. S sees, hears, and pronounces the digits. Cards 
AVA-4a to AVA-lOb are used. 

(5) Auditory-visual-hand-motor presentation. E pronounces the 
digits as in (1) : S writes them, as fast as pronounced by E, upon 
scrap paper: when the series is finished, S at once discards the 
scrap paper, and reproduces the series. S hears, sees, and writes 
the digits. Use the same numbers as in (1), but reverse the order 
of the digits. In this test, it will ordinarily be necessary to devote 
one or two preliminary trials to fore-exercise. 

Variations of Method. — (1) Substitute successive for simul- 
taneous visual presentation in Forms 2, 3, and 4. For this purpose, 
E must prepare cards for insertion in the Jastrow memoiy appara- 
tus,2 so that the numbers used in Forms 2, 3, and 4 (above) may 
now be exposed in vertical columns. In order to secure sufficiently 

^ The metronome should be used in this part of the test to keep the condi- 
tions comparable with the other presentations : it probably, also, tends to 
induce >S's to apprehend tlie digits successively, in the same tempo as that 
used in auditory presentation. For successive presentation, see under 
Variations of Method. 

'' Jastrow's instrument is adequate if E is careful to make the exposures 
regularly, in time with the metronome; it is especially useful for group tests. 
If E desires a more acciu-atc oxi)Osure aj)i)aratus, for individual tests, he 
may employ the Ransclihurj; inenu)ry-;ii)])aratus (now improved by Wirth), 
Bergstrom's rather elaborate exposure apparatus, or G. E. Miiller's modifi- 
cation of the kymograph for 'step-fashion' exposure, as described, in 
improved form, by MrDougall (32). Burt, however, contends that the dis- 
traction produced in inuuature and inexperienced aS's by the sight of unfa- 
miliar apparatus more than counterbalances the advantage of greater 
precision, mechanical regulation of rate and duration of exposure, etc. : 
he used, for successive exposure, a slotted piece of cardboard, which was 
shoved along the column of impressions b,y E (apparcntlj^ at no uniform or 
constant rate, but as fast as proved convenient to S). 



TEST 38: ROTE MEMORY 



365 



long series, the exposure-lever of the instrument is so inserted as 
to articulate with the pegs that provide a drop of 1 in. at each 
exposure. Black letters | in. high (Willson's, Size 5) may then be 
used. These are visible to the normal eye at 50 ft., but E should 




FIG. 54. JASTROW'S MEMORY APPARATUS. 



take the precaution, in classroom tests, to seat myopic S's near the 
front of the room. 

(2) Test the effect, upon a series too long for S to reproduce in 
one presentation, of two, three, or more presentations in immediate 
succession. 



366 ASSOCIATION, LEAKNING, AND MEMORY 

(3) Give repeated tests by the same method, with a series of a 
given length (in excess of *S's span), to test the effect of practise. 

(4) Change the rate of exposure from one impression per sec- 
to one impression in 2 sec. 

(5) Keeping other conditions (form of presentation, length of 
series, etc.) constant, compare S's efficiency under normal condi- 
tions with that under different forms of distraction. Smith 
(44) used for this purpose three different concomitant activities: 
his S's were required during the presentation (a) to tap in time with 
the beat of a metronome, (h) to repeat the syllable la, or (c) to 
add mentally by 2's or by 3's. 

(6) Prepare cards with letters^ in place of digits, for use by any 
of the procedures above described. Use only consonants. Avoid 
alphabetical sequences, or suggestions of words or abbreviations. 

Treatment of Data. — (1) If it is desired only to determine 
aS's memory span, sensu stricto, this is indicated simply by the 
maximal number of digits that can be reproduced without error of 
any kind. 

(2) If, as is more usual in comparative tests, it is desired to 
determine the degree of correctness with which series longer than 
the span are reproduced, the simplest plan is to assign arbitrary 
scores to the various forms of error. Ebbinghaus (15a), for exam- 
ple, scored every omission as 1 error, every displacement from the 
correct position in the series by 2 or 3 places as 0.5 error, and every 
displacement by 4 or more places as 1 error. S's should then be 
compared with respect to their error-score in series of each length, 
separately. 

(3) A more scientific method of determining efficiency is that 
of computing the degree of correlation between the order of impres- 
sions as reproduced by S and their order as presented. This is 
accomplished, following the example of Krueger and Spearman 
(28), by applying Spearman's 'footrule' formula for correlation 
(see pp. 34-35), though, in this connection, it is better to modify 
this formula by counting the sum of all the deviations between the 
two series, rather than the sum of all the positive, or of all of the 
negative deviations. 



^ Use Willson's black gummed letters, Size 5, for the Jastrow apparatus, 
or Size 10 to duplicate the regular printed test-cards. 



TEST 38: ROTE MEMORY 



367 



For treating the data of these memory tests, therefore, the for- 
mula may be written: 

^ " -^ ~ (n2 - l)/3* 

The computation of ScZ needs a little explanation. The following cases 
va.&y be considered:' 

(a) Suppose that »S reproduces all the terms of the original series, 
but not in the correct order. The sum of the deviations is then easily 
computed. In Case A, Table 65, for instance, the sum of the devia- 
tions is 6, and, since n = 10, by the formula just given, R = 0.82. 



TABLE 65 

Use of the ' Footrxde' Method in Scoring the Memory Test {Spearman) 



ORIGINAL 






CASE 


A 




CASI 


B 




CASE C 


SERIES 


Reproduced 


Deviations 


Reproduced 

3 


Deviations 


Reproduced 


Deviations 


3 




3 














3 









7 




7 









7 







7 









4 




2 






2 


- 




? 


2 






2 


2 




9 






1 


9 




1 


9 






1 


9 




4 






1 


4 




1 


4 






1 


1 




1 









1 







2 






? 

















- 




? 












8 




5 






1 


- 




? 


5 






1 


5 




8 






1 


8 




1 


8 






1 


6 




6 









6 







6 









Sum of dev 


lati 


ons 






6 






1.5.9 








9.3 



{b) Suppose, Case B, that certain terms have been omitted. The devia- 
tions of the terms given are figured as before. There is then added the 
amount of deviation to be expected for the omitted terms, on the assumption 
that they are distributed by mere chance. The chance deviation for each 
term is (n--l) -e- Zn. In Case B, then, there are three omitted terms, 
each of which deviates by chance 3.3 places. Hence, the total deviation = 
6+9.9 = 15.9. 

(c) Suppose that S reproduces certain terms more than once, e.g., the 
digit 2 in Case C. In this case, the nearer of the two digits is considered 



1 The author is indebted for these illustrations to a personal communica- 
tion from Professor Spearman. 



368 \s8ooi\rioN. i.kvkmnv^. ano mkmoky 

as the correct one. The other, or duplioatod, term shouUl bo ros^r^lcd as 
an ojuission, ami treated by the formula just jsiven. Thus, in Case C, 
the total deviatiou = 6+o.3 = 9.3. 

(.(i) Suppose that more than the correct luuubcr of terms :ue rcproiluccd: 
here the supertUunis nutnbcrs m;\y be ia:\uMCib since, s;»vc in exceptional 
cases, they bring .-ibout their own pcn;ilt> by disturbinji tlic corrcspoitdeiico 
of order. 

I?. IHK MK.rilOn OF I.KITKK SQlAltKS 

The idea ot' display iiiii' siumllauooiisly a series o( eoiisouaiUs in 
a ^iinplo spatial pattern appears first to have boon sujj^ostod by 
Biuet and Ilonri (^8"): the mothoil was oxtoudoii by Cohn {\-[), wlio 
used it to eoiuparo the rolativo vahios, for a givou ^J. of visual and 
of audit ory-uiot or loaruiu^ii-; aiul it has siuoe boon froquoutly usotl 
as a method of studyinji; ideational typo.^ "Wineh used tiio letter 
square to contrast inunodiate with delayed roprodtietion, and in 
general to study the relation of memory to aiit\ si>\, ;ind seliool 
standing-. Smith (44'> to eon\pare the etYeet oi variotis forms of 
distraction. 

^Materials. — A set of 10 print tnl test-i-ards. Pri>pared forms 
upon which the reproduction is entered. Stop-watch. [The let t(M- 
square cards are priiited in lar^o ty{H> to make the test availal>K> 
for group procedure. The arraitgtMt\i>iit avoids the use ot" collo- 
cations that might serve as aitls to memory. Only cousimaiits 
are used. The blank forms are ruled in 12 squares.] 

METHOD.^Explain to ^' the general nature of the test, lut'orm 
him of the dm-ation of exposuri\ but give him no directions as 
to how he shall attempt to learn the arrangement oi [\\c K>tters. 
Expose the stinuilus card for 2o sec. Let him fill out tlte blank 
form immediately after the ex]H>sure. Allow 20 sih'. for writing. 
Repeat with other cartls, until 4 to 10 trials ha^•e Ihhmi ukuKv 

\'akiatu'>xs of Mktucm^. — (1) Defer the reproductiiut for 20 
sec. (,or 10 sec. to follow CVrhn") after the exi)osurt\ Direct 8 to 
coimt aloud during this interval, from I to 20. 1 mimbtM- per sec, 
in time with K (who may follow a sileitt metrouiune swinging once 
per sec). 'Tlu^ object is ti^ siibihu> or t>liminate the 'iittMuory 
after-image," and to secmv tnie recall in the strict stMis(> oi vcvaW- 

' See, for instance, tlic nioditications introduced for this purpose, in the 
roruell lalnn-atory, as dcscrilicd by Tilchcncr (47, pp. ."Oil tY.1. 



TEBT 38: ROTK ME MO It y '-W.i 

ing aij (;xpf;ricrif;<; w}iif;li Iju'I not, \)<:i:i\ jii:st. provifjii.sly in coriKcious- 

fKt.SS. 

(2j Direct >S' to read the letters aloud, twice over, in concert 
with E, at the rate of 1 letter per sec, Iti^ad by horizontal lines. 
Reproduce with, or without the 20 sec. interval. 

(3) Direct ^S' to repeat aloud, continuously and rapidly, during 
the exposure, the syllaljle 'Ah.' Rtiproduce, preferably, after the 
20 sec. interval filled with the counting. This form of procedure 
obviously favors the visual memory. If more than one trial is 
made, use other syllables, such as 'La,' 'Oh,' etc., to avoid the lapse 
of articulation to automatism. 

(4) i^irect S to count aloud by 2's during the exposure (e.g., 
2, 4, 0, or 3, 5, 7, etc.) or to count backwards from 20. 

(5) After exposure by any of the methods just outlined, point to 
one squar(i after another, in irregular order, asking S to name or 
to write the appropriate letters as rapidly as possible. Or, without 
previous warning, ask *S' to fill in the blank squares in vertical rows, 
or in horizontal rows from right to left. In theory, visual-minded 
/S"s can accomplish this without (;ffort, wh(;reas pur(;ly auditory- 
mind(;d (S"s must retrace their verbal associations to find the neces- 
sary hitters. 

TREATMENT OF Data. — (1) Following Winch, assign 3 for each 
lett(;r in its right position, 2 for each letter one remove to the right 
or left, or above, or below its right position, 1 for each letter two 
removes to the right, or left, or above, or below. 

Specimen of lest given Specimen of a marked paper 

M(3j T(.3; L(Oj R(l; 

LCi) V(2; Y(3j N(3; 

Z(2J B(2j S(lj X(l) 

Score : 23 out of a possible 36. 

(2) li >S' \)(t competent to render introspective accounts of the 
manner in which each letter was recalled and placed, E may, for 
qualitative purposes, compute separately the score for letters 
rfjcalled visually, auditorily, or in other ways. 

C. MEMORY FOU CONCRETE AM; FOR ABSTRACT WORDS 

The essential idea of this test of rrK-mory, as devised by Meu- 
mann, and followed, with some modifications, by Burt, is to com- 



i\I 


T 


\) 


X 


V 


L 


Y 


N 


s 


Z 


\'> 


R 



370 



ASSOCIATION, LEARNING, AND MEMORY 



pare *S's reproduction of a list of concrete, with his reproduction 
of a Ust of abstract terms, given under identical conditions. The 
comparison is based not only upon the simple quantitative effi- 
ciency in the two forms of test, but also, and more particularly, 
upon the qualitative analj^sis of the errors in the reproduced lists. 
Moreover, the test aims to determine not only iS's capacity for 
immediate memorj^, but also his degree of intelligence, or grade 
of mental development. The test rests in principle upon two propo- 
sitions; first, that words whose meaning is understood are more 
easily retained and reproduced than words whose meaning is not 
understood; secondly, that progressive mental development im- 
plies progressive comi)rehension of abstract words. 

]\Iaterial. — For auditoiy presentation, use the followhig lists.* 
For visual-auditory presentation, use the same lists printed upon 
sheets of cardboard with Willson's gummed letters. 

Method. — For group tests, follow Meumann's procedure. 
Explain the nature of the test. Provide each /S with blanks so 
arranged that his reproductions may be properly recorded, the 
lists carefully separated, and dashes inserted for all words omitted. 
Before each presentation, notify the /S's of the number of words 
to be spoken. Enunciate with great care, and without grouping, 
at the rate of one word per sec. Instruct the >S's to write tlieir 



^ The restriction of the abstract lists to words of one syUable, as was done 
by Burt, makes the difference in difficulty between them and the concrete 
lists much smaller than in the material selected by Mcumann. The following 
abstract lists are proposed for use when it is desired to duplicate Meumann's 
conditions : 



Four-term list 

Selection 

Analysis 

Explanation 

Character 



Eight-term list 

Behavior 

Tendency 

Interpretation 

Condition 

Opinion 

Capacity 

Profession 

Connection 



Fiie-tcrm list 

Society 

Symbol 

Arrangement 

Humanity 

Theory 



Six-term list 

Conscience 

Investigation 

Symptom 

Formation 

Complexity 

Experiment 



Seven-term list 

Assumption 

Recognition 

Origin 

Inlkicnce 

Development 

Organism 

Value 



TEST 38: ROTE MEMORY 



371 



lists immediately after the presentation, and as rapidly as possible, 
without trying to 'write their very best,' Guard against interrup- 
tion, intercommunication, or other possible disturbances. Give 
the series in order, as above, i.e., 3-term concrete, 3-term abstract, 
4-term concrete, etc. 



Three-term lists 


Four-term lists 


Five-term lists 


Concrete Abstract 


Concrete 


Abstract 


Concrete Abstract 


Street Time 


Spoon 


Phase 


Ground Tact 


Ink Art 


Horse 


Work 


Pen Scope 


Lamp Route 


Chair 


Truth 


Clock Proof 




Stone 


Thing 


Boy Scheme 
Chalk Form 


Six-term lists 


Seven-term lists 


Eight-term lists 


Concrete Abstract 


Concrete 


Abstract 


Concrete Abstract 


Desk Space 


Ball 


Craft 


Coat Law 


Milk Creed 


Sponge 


Myth 


Girl Thought 


Hand Pride 


Glass 


Rate 


House Plot 


Card Guile 


Hat 


Cause 


Salt Glee 


Floor Pledge 


Fork 


Style 


Glove Life 


Cat Cue 


Stove 


Youth 


Watch Rhythm 




Post 


Mood 


Box Faith 
Mat Mirth 



Variations of Method.— Follow Burt's plan of working with 
individuals, displaying the words successively, and directing S 
to pronounce them as displayed, in concert with E.^ Lists of 4 to 8 
nonsense syllables may also be included, as in his tests, for com- 
parison with the easy and with the difficult words. 

Treatment of Data. — The lists are to be examined first quanti- 
tatively, secondly qualitatively. The results for each S are entered 
upon a scheme like the following, which is transcribed, with some 
modifications, from Meumann. 



ILLUSTRATION OF THE TREATMENT OF DATA IN MEMORY FOR WORDS 

Subject: Adolph L. Age, 8 years. 

Types of Error Number 

1. Memory errors (omissions and displacements), concrete lists. 5| 

2. Memory errors (omissions and displacements), abstract lists 7} 

3. Insertions 4 



* It is to be expected that Burt's method of presentation would have pro- 
duced, as it did, less characteristic differences between the two kinds of 
words than were found by Meumann. An unfamiliar, or but slightly fa- 
miliar word has an obviously better chance to be recalled if it can be seen, 
heard, and pronounced, instead of being merely heard. 



372 ASSOCIATION. LEARNIXG, AXD MEMORY 

4. Insertions of nonsense words 1 

5. Fusions 

6. Perseverations 3 

7. Regressive inhibitions 1 

S. Complete i-eversals 1 

9. Substitution of synonyms 

10. Substitution of concrete for abstract I 

11. Wrong formations 4 

12. ^lisunderstood abstract terms 5 

13. Spelling Very bad 

14. Handwriting Undeveloped and ugly 

(1) and (2) Omissions are represented by the integers, i.e., Adolph L. 
omitted five words from the concrete lists, 7 from the abstract (.the test 
was carried to the 7-term list only). Displacements from the correct order 
count ^ error when the displacement is by one remove only, | error, when 
more than one remove (save that with younger children, as in the case above, 
all displacements count ^.) Hence Adolph L. made 2 displacements in the 
concrete, 7 in the abstract series. 

(3) Insertions are the total number of words added. These are counted 
as 1 error each, unless the added word has some similarity of sound to a 
word actually presented, in which case it counts § error. 

(4) This rubric embraces the relatively infrequent addition of a meaning- 
less tvord that has no similarity in sound or spelling to any of those pre- 
sented. 

(5) Fusions of two or more totally independent, successive terms into a 
single meaningless term are a very significant form of error, which appears 
in abstract lists written by »S's of poor intelligence, e.g., Organ and Gattung 
are reproduced as Orgaitung. Mostly found in children 8 and 9 years old. 

(6) Perseverations are indicated by the recording by <S in a given series of 
a word that had already been reproduced in an earlier series. If frequent, 
this is a sign of a low intelligence, lack of self-control and of critical judg- 
ment. 

(7) Regressive inhibitions. Failure to reproduce at least one-half of the 
terms given is, as a rule, to be interpreted as regressive inhibition. This 
condition is commonly attributable to a state of confusion into which a 
child is thrown, when he is suddenly 'overwhelmed' by the task, when 
everything 'flies out of his mind,' he 'loses his wits,' and is unable to accom- 
plish even a fraction of his normal performance. The same thing is seen in 
adults under conditions^ which are difficult for them. Since, Meumann 
argues, this is essentially due to inability to force attention, lack of this 
ability is a token of poor general ability, and hence of low intelligence. 
Failure due to absolute lack of intent to succeed miist, of course, be distin- 
guished from the lack of ability to succeed. 

(S) Complete reversal of word order, either in a large portion, or in the 



TEST ?jH: rote memory 373 

whole of a list is "a peculiarly puzzling phenomenon." There are occa- 
sionally met, for instance, cases in which a series of 8 words are all written 
in the reverse of the order presented.^ 

(9) The auhslitut'ion of syrujnyms refers to the easily intelligible cases in 
which a word of like meaning, but different sound, replaces the word given, 
e.g., roafUoT street. 

(lOj The subHlitution of concrete for abstract words refers to the use of 
concrete terms of similar sound, whether of similar meaning or not, e.g., 
cowH for cause, simple for symbol. E must use his judgment here in making 
allowances for faulty spelling. 

(11) Wrong formations, in especial the use of wrong endings, constituted 
a prolific source of error in the German tests, particularly with abstract 
words, e.g., Glaubheit for Glauhe. Errors of this type may be expected to be 
less frequent in the le.ss highlyinflected and compounded English language, 
but occasional instances will be found, e.g., seleclness for selection. 

(12j Misunfler stood abstract terms is to be regarded (as the author under- 
stands it) as expressing the sum total of misapprehended abstract terms, 
whether the misunderstanding is indicated by substitutions, faulty endings, 
fusions, very faulty misspellings, or in other ways. 

(13) Orthography constitutes a secondary symptom of intelligence. In 
order to estimate spelling fairly, papers are ranked as 'poor' in spelling 
only when the sum of misspelled words is oO% or more greater than the 
average number of misspellings for *S"s class. 

(14) Handwriting constitutes another secondary symptom of intelligence, 
and is merely rated, as fairly as possible by comparison of numerous papers, 
as good, average, or poor. 

These 14 rubrics are filled out for each S. For the estimation of 
memory capacity, pure and simple, Meumann takes Nos. 1 and 
2; for the estimation of intellectual ability, he divides the rubrics 
into three groups, (Ij those that serve as indirect indexes of intelli- 
gence (Nos. 1, 2, and 3), (2) those that serve as direct evidence of 
intelligence (Nos. 4 to 12, including a statement of the relation of 
Nos. 1 and 2), and (3) those that serve as secondary symptoms of 
degree of mental development (Nos. 13 and 14). Now, for each 
of these condensed indexes, the grade of each S is indicated as (1) 
above average, (2) average, or (3) below average, and final compari- 
sons and correlations are based upon these grades. 

' The author is inclined to regard this phenomenon as a simple case of 
attempt on the part of a few /S"s to get the series right by beginning with the 
last word heard and working back to the first section. S may have inten- 
tionally disregarded instructions to reproduce in the order given, or may 
have interpreted these instructions to include the reverse order as accepta- 
ble. In other words, it scarcely seems probable that the child does not 
know that he has reversed the order of presentation. 



374 



ASSOCIATION, MOAUNlNd, AND MKMOIiY 



TAMl,!'; (1(1 
Xoniis of Miiiionj Spun for Ditjils, us ( 'ondilicinit hi/ .K/c {Snicillci/) 



Alio 


AUDITOUy Bl'AN 


V1.HU.V1. HI'.VN 


A mo 


AiiDnoiiv 


7 


6 


5 


14 





8 


5 


5 


15 








f) 


li 


10 


() 


10 


(■) 


1. 


17 


' 


II 


(> 


li 


IS 


(• 


I'J 


(') 


7 


10 


7 


i;{ 


ti 


7 







( ii'iNKifAi. l{,KSiii/rs AND (. \)NcM AisiONS.- ( Nonits of ptrfornMiice 
for ihv (Hj>;it test (SmcHiloy's iiK^lhod) arc ro[)r()iluco{i jii Tables 
()() and ()7, for Iho 1(>M(m- sciium" molhod (IVoin Winch) in Tabic 08. 

Nci(.li(M- Mcuin:tnii nor Hnit has j)ublishc(l dala for the word 
test in (h(> lonu ol' noiins. Typicnl ptM-forniMnct's for other varieties 
of nuMuorv (vsl will be fouiul in ( li(> l:i,bl(\s ( luii follow. 



Dtrrlopninit of Mcmori/for Dii/its {Snicdlcy) 



•lONl' UIOIMIODIK'KII 



Yoani 


Moittim 


1 


\udltoiy 


Vlsuftl 


7 


K 


1" 
19 


30.4 


35.2 


8 


8 


AS 


•11 


■12.S 


9 





100 


•1;") 


17. -t 


10 


6 


S9 


19 1 


51.0 


11 





91 


.V) , 1 


01.7 


12 


6 


9:5 


55 , 7 


72,3 


18 


7 


109 


57 9 


70 . S 


14 


6 


111 


OC) 2 


SO 5 


15 





91 


Of. . 


7S . 2 


10 





77 


00,9 


SI. 3 



50 



12 



SI. I 



70.0 



Ti'is'i' .'iS: uoTK iviii;ivi<»uv 



:i7: 



(2) Dr.pcndcncc, on hcx. 'V\\v. inv('Hl,i}z;ji,l.i()riH of holl-ori, Kirk- 
|)u(,ri(!k, (!allvinH, S(!lmyt(!ti Crahhi (i!)), iiiid roliliiijuin all iinrco in 
sliowinp; w. Kiipcriority of ^irls over hoys niid of woincn over men 
in (,(',s(,H of iiniM(!(liiit(i or of '(l('lji,y('<r {'.\ diiysj inciiiory. liohKicii'.s 
(,('s(„s wil li varied malcriidH ('I'liblc 7^1) likc^wisd hIiow('(| \,\\n\, nirl.s rc- 
proddccd inon;, hiil, Mial- boys wen; inorc! !i.|)t l.o ^;((1, Mk- order 
rin'lil,.' Ncil-Hcliajciff also (M)iiclii(lc(l (,li;i(, ji;irls uiiide more illiisor-y 
(M-rors (eHpeeiidly )i,i n,(i;es *.) l.o I I), lie nlso foiiiid (linl, hoys liad l.lie 
heller tiieinory For vr\[\ ol)je(;|,H, ^ii'ls for- iiiiinhers !Uid words, irr 
wliieli Uii'y siir |)!r,ssed l)oys, p.-rrlif^rdM-r-ly diirirrjj; llieyejus I I l.o M. 

'r'Aruj'; oh 
Mr.inoril-Jor fjcllcr Sr/uarcn, in lirhUlda U> /{(/<: aiuL I'vucUhc, {Winch.) 



■oaoot. 


NUMUnU 
TKHTini) 




AVIBI 


lAIIID AilfO 


lOx-vii. 


r, 


11 


yr-H. 


;{ inoH. 


vii. 


5 


i:i 




f) " 


vi. 


5 


12 




:{ " 


V. 


5 


11 




4 " 


iv. 





10 




5 " 


Hi. 





!) 




" 


ii! 





H 




2 " 



Zi.H 
20.3 
20.8 
18.4 
21. ;{ 
Ml 
I."'. 2 



Wissler-'s l.:r,l)iil;i,i;rori of lire IVeKliirrciri fe.sfs id ( 'olurrrl.r;r litri- 
versily :r,nd liar'iriird (College revorls sex dilfereriees irr rrierrror-y 
span for dif^itH Uiai an; I(!HH I Iran llie I'. 10. of l.he ;iver;ij;es, .-uid 
flial. ;avor the rrreri for .•iiidil.ory, :i,rid Ihe women foi- vrsrinl 
H(TieK fTahle 7()j. 





■.,. 


Sl,H 


WIOTohLs 


ydio'j'oMU 




20.0 


31.7 




27.9 


31.1 




82.0 


34,0 




22.9 


20.3 




24.8 


20.0 




17.7 


19.7 




1(1 8 


17.2 



fur 
.'1 Hl*l,N 


28,1 


28.4 


3 LP 


22.5 


24,2 


17.1 


ir»,7 



J'<:raml,(i{/t: of A cr.urt 


icy ill. Mc'imn 


!/ for "i-placc. N ii.mh 


■.r:: iSrluiylc/n) 






M(;HNIN(I 


AirilullNOON 


I''irH(, (,(;hI, 
(Afl.fsrtiooii lirHl.) 


MoyH 

(JirlH 


fiS.l 
09.0 


04.0 
77.6 


Second 1/CHt 
(Morning firHl.) 


BoyH 
(JiriK 


57.9 
02 . i) 


35.0 
66.1 



' Noi(! n.u:\Um>\\y. f<'i:iil(,H in Uic. 'VchI of K.^poil, (No. .'{2, |.. MW,). 
'■'TIk! fi;iilH of Uiin t^ioiip proved l.o li!i,ve \)i:v.\\ of H\>i\v.\u\ iihilil.y. 



376 



ASSOCIATION, LEARNING. AND MEMORY 



(3) Dependence on age. That memory capacity increases in 
general from the early to the late school years is illustrated in 
Tables OG, G7, 08, 71, 72, 73, 75, and 78. The general evidence is 
fairly clear that the improvement is steady up to puberty, but that 
it suffers fluctuations after that period. Several investigators ad- 
duce evidence that corroborates the popular notion that there exists 
a special 'memory period,' or stage of maximal efficiency some- 
where in the 'teens/ when memory is stronger than it is later. For 
example, the very careful work of Pohlmann, with varied materials 

T.\BLE 70 

Sex Differences in }[eniory Span for Digits i)i College Freshmen (Wissler) 





AUDITORY PRESKNT.\TION 


VISU.V 


t, PUESKNT.VTION 




Number 


Average 


P.E. 


Numhor 


Average 


P.E. 


Men 
Women 


266 
-42 


7.6 
7.3 


0.4 
0.5 


142 
42 


6.9 
7.3 


0.5 
0.4 



and varied forms of presentation, yields the net results (method 
of retained members) shown in Table 71, in which maximal effi- 
ciency is indicated at 14, followed by fluctuations, without real 
improvement through the adolescent period. Bourdon (10) could 
discern progress from 8 to 13, but not from 14 to 20. Bernstein and 
Bogdanoff, in testing memory for geometrical figures by the 



Xel Efficienci/ of Varions Memories, in Relation (o Age {Fohlmann) 
10 I 11 1 

41.4 I 55.7 59.1 ' 62.1 



Average 
Capacity 



68.9 55.3 62.9 58.6 ' 58.0 65.4 68.3 



method of recognition, fouuil tliat 23 »S's aged 14 and 15 averaged 
better than the 55 adults that they tested. Wessely (49), who 
tested retention during a long period (1 and 2 years), was con- 
vinced th{it ability to retain and reproduce poems is maximal at 
the^'-ears 12-14, and that vocabularies (Latin-German) are repro- 



TEST 38: ROTE MEMORY 



377 



duced more accurately at the expiration of 1 to 4 weeks, when 
learned by 12-year, than when learned by 15-year old S's. Similar 
assertions concerning the relative amount of retentive capacity 
for poems by children and by adults are made by Larguier (29, 
185 ff.), while Binet believes (5, 259 ff.j that children have the 
better retentive capacity, and adults the better attentive capacity, 

TABLE 72 
Dependence of Memory Span for Auditor ij Digits on Age (Jacobs) 



AOB 


8 9 


10 


11 


12 13 


14 


15 


16 


17 


18 


19 


Number 


' 




















tested 


8 13 


19 


36 


41 42 


42 


72 


66 


50 


30 


14 


Average 






















Span 


6.6 6.7 


6.8 


7.2 


7.4 7.3 


7.3 


7.7 


8.0 


8.0 


8.6 


8.6 



Over against this evidence for a decline of efficiency after 14, we 
have the figures of Jacobs (Table 72) and the emphatic statement 
of Smedley (43, p. 49), based upon his Chicago results (Table 67), 



TABLE T.i 

Dependence of Memory for Auditory Digits on, Age {Ebbinghaus) 

(Average Number of Errors per Pupil in Two Series) 



AVERAGE AGE 


8-DIGIT SERIES 


9-DIGIT SERIES 


lO-DIOIT SERIES 


6 TO 10 DIGITS 


10.7 


3.1 


5.1 


7.4 


17.8 


12.2 


2.9 


4.7 


7.9 


17.5 


13.2 


1.5 


2.6 


4.2 


9.1 


14.4 


1.6 


3.0 


4.9 


10.5 


15.5 


1.0 


2.1 


3.7 


7.6 


17.1 


0.8 


1.4 


3.9 


6.5 


18.0 


0.9 


1.4 


3.4 


6.1 



that "there is no 'memory period,' no period in early school life 
when the memory is stronger than it is at any later portion of the 
child's life." Smedley's records do, indeed, show that "auditory 
memory develops rapidly up to about 14 years of age, and but 
slowly after this period. The visual memory seems to develop 
rapidly up to about 15 or 16 years of age." . . . "It will be noted 



378 



ASSOCIATION, LEAKNING, AND MEMORY 



90n/o 

85" 
80" 
75" 
70" 
65" 
60" 
65- 

50" 
45" 
40" 
35" 



,7 8 9 10 11 12 13 14 15 16 17 18 19 20 















































/ 


/\ 


\ / 


/ 












c 


f 


/ 








V / 

V 














/ 
/ 
























1 

1 

! 


/ 


r 


!^ 


&> 


^^<\ 






/ 










1 

1 
1 
1 


/ 


1 




















1 




/ 


















— - 




1 




J 


















1 

> 1 

'7 


1 






















/ 


/ 
























// 
























/7 


























// 
























/ 



























Fig. 



55. DEVELOPMENT OF MEMORY FOR DIGITS. 
From Smedley. 



rjosT :i8: uotk memory ;^79 

[ Fig. 55] that, in the early life of the child, tlu; auditory memory 
is stronger than the visual m(!mory; after ahoiit 9 years of age, 
the visual memory of most of tlu; ehildren Ixjcoines stronger than 
the audit(jry memory, and continues to dcveloj) irK^re rai)idlythan 
the auditory memory throughout school life. Yet, even in the 
high scho(jl, th(!re still reir)ains a siriall i)roportion of the pupils 
whos(! h(!aring memory is the stronger." 

The dei)endence of different types of memory upon age has been 
studied esp(;cially by N(!ts(;haj(!ff and by J^obsien. They agree 
substantially that, while the various forms of memory improve 
with age on the whole, there are periods of rapid development, 
followed by no improvement or even by a reduction; that while, 
on the whole, the greatest improvement occurs during the years 
10 to 12, and development is retarded after 14, yet the different 
forms of memory, considered specifically, develop at different 
rat(!S, and at periods that may not coincide in the two s(!xes. 
Thus, in boys, memory for objects is at first best developed, then 
follow, in order of chronological development, memory for visual 
t(!rms, for acoustic terms, for actual sounds, for tactual terms, for 
mnnbers, for abstract terms, and finally for emotional terms. For 
girls, the chronological order is: visual terms, objects, sounds, 
numbers, abstract terms, acoustic terms, tactual terms, emotional 
terms. Special stress is laid upon the parallelism of devehjpment 
})etw(;en memory for ruimbers and memory for abstract terms. 

In M(!umarm's word-list t(;sts, those types of error that indicate 
poor intelligence decreased with age, until, at 14 and 15, instances 
of misunderstood abstract terms were limited to about 10 per cent 
of his S'», while meaningless fusions, meaningless insertions, and 
the substitution of concrete for abstract terms had nearly dis- 
appeared, and the memory for abstract terms had so increased as 
frequently to be superior to that for concrete terms. It fellows 
that age must always be taken into account in the interpretation 
of this test, particularly in estimating intelligence by it. 

(4) Dependence on the nature of the material, (a) When digits 
and consonants are given under the same conditions, digits are 
easier to reproduce (Jacobs, Sharp), especially during the years 8 
to 13 (Bourdon). But, if 10-place series are presented auditorily, 
thrice, the order of excellence for recall is (1) consonants, (2) 



;>S0 ASSOOIAI'ION. l.KAUMNt.;, VNO MKMOKY 

nanios of objootf^, i^o^i 'J-pl:\oo uun\lHM-s. i^ uousctiso syllables 
vPohlinnnnV 

{h) NotsohajolY. Lobsion. Pohhunuu, and loss olaboratoly 
Kirkpatriek and Calkins, have I'oiuparod nioiuory for series made 
up of real objeets. of numbers, of sounds, and of words having 
eharaeteristieally visual, auditory, tactual, or emotional associa- 
tive meanings. Table 74 gives illustrative results from Lobsion. 
Pohlmami, hoNvever, concluded that the assumption of NetschajelY 
and Lobsion that the proseutation of visual, auditory, and other 
terms arouses the visual, auditory, and otiu^r imagery that their 
meaning implies, is erroneous, so that the results of tliese investi- 
gations are of little real significance. 

PMU.K 74. 
Mitnory for 9-tcrm Sfrit-g of Dijhrrut /v/'»i</,s' {Lobsini) 



OV SiRKIES 



SOOUS IN PKU l-KNT I'OKKKlT 



BOTS 



91.4 


71.8 


(V2.2 


71.0 


67,2 


60.2 


59.4 


23. S 



Real objects 82.2 

Auditory numbers 64. S 

Sounds r>9 . 6 

Tactual terms 64.2 

Visual terms 60.6 

.\uditory tern\s 59.4 

Emotional terms 31.2 

Foreign t ernis 24.0 



Kirkpatrick. and after him Miss Calkins, found, like NetschajetT 
and Lobsion, that memory for objects (^or pictures of objects) was 
superior to that for words, both for immediate and for delayed re- 
production; in the latter, for example, there wore recalled seven 
times as nu\ny objects as words. The same investigators deter- 
mined the order of excellence for recall of ditYoront kinds of wonis 
to be: — visual terms, auditory terms, names of objects. 

(c) Up to the 12th year, concrete words are roproducot.1 bettor 
than abstract words, but 14 and 15-year old 8's frequently make 
better records with the latter (IMeumann') . 

(d) Related terms, i.e., a series of words not in a sentence. 



'IKST '4H: juj'ii'; .MioMOJty ;>S1 

hut readily aHH(jcialcd wiiJi one another, are more easily recalled 
llian unrelated words. For data, see Table 75 from MisH NorH- 
vvorthy. 

(e) Material ko arraturcjl as to aid local/lzoMon is more easily 
rememh(;red, especially by children. For example, 12 consonants 
in the letter-square form are easier to recall than 12 consonants in 
a single line; similarly, di^^its pronounced in rhythm are easier to 
recall than digit.s prfmounced in even tempo fMiJller and Schu- 
mann). Pohirnann found g-roufjed series to be the easier in lo'j 
of 144 trials. 

TAUIJO 75 
NorniH for Memory of /iclalcA and of Urtrclaled Words (Nornworlhy) 





Related Wo; 


IDH. 288 fjA 


HKH 


tJ.N«KI.ATBI.> Wf 


>ia>H, 270 Cahkm 


A OK 


/iOV8 


XhH 


uoys 




<ilMM 




Mcdlau 


P. E. 


Median . 


P. K 


'. Median 1'. K. 


8 


13.0 ' 


1,0 


' 13.0 


1.6 


.1.1 1 


1.6 


11.6 1 1.3 


u 


14 


2 


14 


1.7 


12.2 


1.7 


12.4 1.4 


10 


ir, 


17 


15.3 


1.9 


12,2 


1.7 


14.4 1.4 


] 1 


ir> 


17 


10 5 


1,7 


12.5 


1.8 


14.3 1,4 


12 


if) 4 


1.8 


10,0 


1.0 


12.8 


1,8 


14,0 1,5 


13 


10.5 


1.8 


17.0 


1.5 


13.5 


2,1 


13 5 1.5 


14 


1G.9 


1.3 


17.5 


1.5 


13.7 


2.2 


14.0 1,5 


\r, 


10.0 


1.3 


17.5 


1.5 


13.7 


2 2 


14,0 1,5 


Hi 


17,0 


1.3 


17.8 


1.5 


14.0 


2.2 


14.5 1.5 


A.I lilts 


10.5 


1.5 


17 


1.:) 


12,8 


1.2 


13.0 1.4 



(5j Dependence on HenHe-de/parimenl directly stimulated. It is 
(jvident that a complete isolation of the different modalities can not 
be accomplished by diff(!rent forms of presentation: e. y., auditory- 
minded *S"s may actually retain and reproduce impressions pre- 
sented to the eye in auditory, f)r mainly in audit(;ry terms, and so 
on. Ten nouns heard are, by young >S"s, recalled better than the 
same number of nouns successively seen, Vjut above 15 years the 
reverse is true dlawkinsj.' More extensive comparisons have been 

' Cf. Bmedley'H evidence of the superiority of auditory rnernory in youni^er 
S'h (Table 67 j, and Pohlmann's reHults (Table 70j. 



382 



ASSOCIATION, LEARNING AND MEMORY 



made by Pohlmann and by Smedley. Table 76 indicates a su- 
periority of auditory- visual presentation over either auditory or 
visual presentation, alone — a result in accordance with Smedley's. 
Pohlmann also investigated the effect of these three forms of 
presentation upon numerals and nonsense syllables, with the re- 
sult that for 230 Volksschule girls, using 10-term series, given 
thrice, the percentage of accuracy was, for visual-auditory 53 per 
cent, for visual 52 per cent, and for auditory 42 per cent, which 
agrees in substance, so far as it goes, with Smedley's results for 
digits. This investigator found the order of superiority to be: (1) 
auditory-visual-articulatory, (2) auditory-visual, (3) auditory- 



TABLE 76 

Dependence of Memory upon Form of Presentation (Pohlmann) 
{Percentage of Retained Members, 10-Term Series, 850 Pupils, 9-14 Years ) 



NATURE OF MATERIAL 


FORM OF PRESENTATION 


PER- 
CENTAGE 
RETAINED 


1. Actual objects 

2. Actual objects 

3. Names of objects , 

4. Names of objects 

5. Names of objects 

6. Names of objects 


Shown and named bj' E.. 
Shown, only, successively 

Seen and heard by 5 

Heard, only, by S 


72| 

70 

56t^, 

55i 

501 

491 


Seen, heard, and pro- 
nounced by S 



In the upper ok 



5 becomes superior to 4. 



visual-hand-motor, (4 and 5) visual or auditory (depending on 
age). Illustrative figures for S's aged 18 years are, for the five 
forms just mentioned, 88.4, 86.9, 82.4, (circa) 80.0, and 66 per cent, 
respectively. Combined appeal is, then, most powerful, but the 
task of writing proves somewhat distracting. 

(6) Successive vs. simultaneous presentation. If 15 words are 
exposed simultaneously or successively for equivalent lengths of 
time, successive presentation is easier for young, but simultaneous 
for older children, according to Hawkins. 

(7) Dependence on number of presentations: repetition. Pohl- 
mann, Lipmann, Smedley, and others have found that hearing a 



TEST 38: EOTE MEMORY 383 

series thrice or twice, instead of once, improves its recall. How- 
ever, Hawkins found two hearings less effective than one or three. 
It is certain that more is accomplished in the first hearing than in 
a large number of repetitions, and that the effect of repeated pre- 
sentation is different in different >S's, so that individual differences 
are more marked after many hearings than after one hearing 
(Smith). Smedley's test of 38 10-year pupils, with auditory digits, 
gave, for the first hearing 47 per cent, for the second 55 per cent, 
and for the third 59 per cent correct reproduction. In some of 
Smith's tests, 12 presentations did not double the efficiency at- 
tained in one presentation. 

(8) Dependence on rate and duration of exposure. Bergstrom's 
tests (3) indicate that nonsense syllables exposed at the rate of one 
in 0.77 sec, with durations of exposure of .041, .082, .164, and 
.318 sec. yield practically the same results, though there is a slight 
preference for .82 sec. 

The same investigator found that, both with auditory letter 
and word series and with visual nonsense-syllables series, a rela- 
tively slow rate of exposure (1.5 to 2 sec. per term) yielded more 
accurate results than a faster rate (one term in a fraction of a 
second) . The slower rate is especially helpful in lists of words, and 
for those »S's that try to develop associations between the terms as 
they are presented. Bergstrom summarizes by saying: "The 
acquisition and retention of a series of familiar associable words 
varies approximately as the logarithm of the interval at which 
the words are spoken" (3, p. 221). 

(9) Dependence on interval hetwee7i presentation and reproduc- 
tion. Relatively short intervals make, apparently, but little 
change in reproduction. Thus, Winch could discern no clear 
differences in the reproduction by school children of letter squares, 
with or svithout a 25-sec. empty interval between presentation and 
reproduction. 

Binet and Miss Sharp compared immediate memory with 
'recapitulatory' memory (memory of conservation); they both 
noted that the word lists in immediate reproduction seemed to be 
held largely by sound (so that, for example, such errors o.^ flower for 
floor were common), whereas lists reproduced 3 min. later appear 



884 ASSOCIATION, Ll'.ARNING, AND MEMORY 

to be held more often by nieauinj>;, since "the errors are usually 
additional words sugsestod from analogy of sense" {e.g., dog 
suggested by cat, cold by v^intcr, etc.)' 

Attention has already been called (4, b, above) to tlu> demonstra- 
tion by Kirkpalrick and by Calkins that the reproducibility of dif- 
ferent forms of nvaterial is not equally affected by a 8-day interval. 

(10) Effect of distract ion. Smith's use of the method of letter 
squares (44), with and without the distraction of concomitant 
activities, shows the order of efficicMicy under these conditions to- 
be, from best to worst: — (1) Avithout distraction, (2) with tapping 
to the beat of a metronome, (3) with repetition of a vowel, and 
(4) with counting by 2's or 3's. C^ohn, with the same test, found 
that an auditory-motor ;S was more seriously disturbed by auditory- 
motor distractors than a visually minded S, and that, when such 
distraction is used, visual memory steps in to aid, provided >S's. 
constitutional make-up (Anhrgc) will at all permit (14, p. 182). 

(11) Dependence on practise, (a) Practise produces a measura- 
ble increase in the memory span (Bolton). In the use of nonsense 
syllables, indeeil. the practise etTect can be discerned even at the 
expiration of 60 days of experimental work (Midler and Schumann) . 

Winch, from his use of the hotter square, as well as of auditory- 
letter series, not only declares that there is a ''marked and almost 
invariable improvement," but ''that 'pure memory' is markedly 
improvable by practise" (50, p. 134). Thus, 38 aS's, ages 8 to over 
14, obtained, in 3 sets of 10 tests each (1 week between the 1st and 
2d, and 2 weeks between the 2d and 3d), the average scores 20.6, 
24.4, and 26.6 (averages of the scores of Table 68). 

(6) The transfer of practise from the specially trained form of 
memory to other forms of memory would appear, from theoretical 
grounds, to be limited to those cases in which the material, content, 
or form of procedure of the other forms were related to the mate- 
rial, content, or form of procedure of the trained form. This is 
essentially the conclusion reached by Ebert and Meumarm (16^ 
p.. 200), who say: ''The objective results of our experiment show 

' The temloncy of adults is away from roto nuMiiorizing in favor of a inom- 
ory of meanings. It would, then, be interesting to see whether children 
exhibited these same tendeneies that Sharp's university students did. or 
exhibited tiiem in as marked a degree. 



riOST ;>V: ItO'lK .MIOMOHY 1^85 

that special nuiinory pra(;tis(! is acc<)iiii)ani(;(l hy a {^(iiicral iinprovc- 
iiicrit of memory. Tljis concomitant improvement does not, 
however, extend equally to the othca- 'memories,' but apf^sars to 
follow the law that the specific memories f)articipate in the 
improvement directly in proportion as they are related in con- 
tent, or in media and mc^thod of iearnint^ to the specifi(t memory 
that was trained."' 

Winch has f)een led, ))y experiments in memorization of poetry 
and historical prose (51), to take the more radical stand that 
"improvement, gained in practise in memorizing one subject of 
instruction, is transferred to memory work in other subjects whose 
nature is certainly diverse from that in which the improvement 
was gained, ... at least so far as cfiildren of thes(j ages and 
attainm(!nts are concerned." 

On th(! other hand, Wessely directly controverts the conclu- 
sions of Ebert and M(!umann, and says that th(!re seems to be no 
formal practise effect of memory. 

(12) Dependence on phy.sical capacity. Hoili Ncischajcff an(i 
Srncidlfiy find that pupils that are larger, stronger, and Initter de- 
v(!lo{)ed physically have })ett(!r memories than tlxjse of the con- 
trary type. "This suggests," says Smedlfjy, "that th(; immediate 
sense memory is dependent upon good brain formation and nu- 
trition." (See 43, pp. 58-59, for numerical evidcmcc;.) 

(13) Dependence on fatigue. Though fatigue may aff(!ct im- 
irKsdiate memory and undoubtedly does so when severe, it is 
difficult, if not impossible, to arrange memory tests to serve as 
an ind(;x of the degre(! of fatigue;. On this point, we have the 
unanimous verdict of Holton, Eby)inghaus, Schuyten, and Smed- 
ley. The prime difficulty lies in th(! fact that either practise or 
ennui affects the r(;sults more than fatigue. Hitter gave up the 
determination of fatigue by span tests with numerals, but he did 
achieve results which h(; considers of sj)ecial value by the use; of 
0-terni series of two-syllabled nouns. With this material, he finds 
that errors increase witli fatigue;, and h(; goes so far as to assert that 
this test is the best on<; availabh; for t})(; investigation of fatigue. 



'ConHuli K\>itri luid Mr;ijiniUiii for fuillicr di.scuHHion of tlie iiUimiiU; 
nature; of th<; trariHfcr cilccA. 



386 ASSOCIATION, LEARNING, AND MEMORY 

(14) Correlation with tnental ability. Coiiclusioiis as to the 
relation between meniorj- capacity and general intelligence range 
from a flat denial of such relationship, as by Bolton and by Eb- 
binghaus' (Table 77). to assertions like that of Jacobs that there 
is a "notable concomitance" between school standing and "span 
of prehension.'' A considerable number of investigators, among 
whom should be cited Binet, Bourdon, Burt, Pohlmann, Smedley, 
Winch, and Wessely, have found at least a fairly good degree of 
correspondence, but have expressed their conclusions with cer- 
tain restrictions or explanations that merit our consideration. 

TABLE 77 
Relation of Memory of Auditory Digits and Intelligence i^Ebbinghaus) 







AVERAGE NUMBER OF ERRORS PER Pl'PIL 




Bright 
j Group 


Average 
Group 


Dull 
Group 


9-digit test... 




8-1 


87 
117 
319 


84 


10-digit test 




147 


13a 


6-10 digit tests, 


collectively 


318 


:^o:5 



Binet (5) contrasted 6 dull and 5 bright boys, and found that, on the whole, 
the latter surpassed the former in memory: the difference, as in his tests 
of other traits, was, however, more evident at the fir.st. than at any subse- 
quent trial. 

Burt (12) estimated intelligence in four ways and measured memory 
for concrete words, abstract words, and nonsense syllables. The correla- 
tion between intelligence and memory proved to be .60 for Elementary 
School boys, and .82 for Preparatory School boys. Burt, however, did not 
substantiate Meumann's results (see below) as to the relative superiority 
in bright children of memory for abstract words. 

Pohlmann, like Binet, dealt with contrasted groups. He concludes 
that, while in general the better pupils have better memories, there are 
numerous exceptions, particularly in that poor pupils may do as well as 
bright pupils in the memory tests. 

' From the data of Table 77, Ebbinghaus concludes (15a, p. 430) : "That 
sort of primary memory power that is involved in the immediate and exact 
reproduction of a series of relatively simple impressions is, accordingly, not 
more strongly, but, if anything, slightly more weakly developed in better 
than in poorer intelligences." Almost the only similar conclusion is that 
of Wissler, who found a correlation of but 0.16 between the class standing 
and memory capacity of 121 Columbia freshmen. 



TEST :i8: ROTE MEMOllY 



387 



Grade 
HI 



IV 



VI 



VII VIII 

























1 












1 










1 

1 
1 

1 












* 








M\s\ 


IkL..' 




/ 




/ 


/ 




J 


/ 




/ 




4-^~~^ 


J 




/ 




>^ 


y 








^ 


X 








/ 


/ 










/ 













Fig. 56. memory capacity of 12-year i^ui^ils, by grades. 
(From Smedley.) 



388 



ASSOCIATION, LEARNING, AND MEMORY 



Smedley declares that the "parallelism between school standing and 
memory power holds good throughout school life" (43, p. 54), and demon- 
strates this by reference to mass results distributed to show the memory 
capacity of pupils of a given age in different grades (Fig. 56), or the ca- 
pacity of pupils at and above grade as compared with the capacity of pupils 
below grade at different ages (Table 78). 

Winch's letter-square tests convince him that "general mental ability 
[rank in examinations in reading, arithmetic, dictation, and English 
composition] is accompanied by 'good memory.' " "With two exceptions, 
no girl whose memory mark is relatively low has a high place in class." 
" 'Good memory,' though usually accompanied by general efficiency, is not 
TABLE 78 





Relation of Memory for 


Digits and School Standing {Smedley) 




Number 
Tested 


AUDITOHY 


VISUAL 


Age 


Average Standing of 1 Average Standing 
Pupila At and of Pupils Below 
Above Grade Grade 


Average Standing 

of Pupils At and 

Above Grade 


Average Standing 

of Pupils Below 

Grade 


a 


99 


47.8 


39.7 


50.3 


41.9 


10 


88 


54.4 


42.7 


61.6 


46.2 


11 


91 


59.0 


48.6 


69.4 


53.3 


12 


92 


62.6 


52.2 


76.7 


66.0 


13 


110 


70.4 


64.3 


80.7 


72.3 


14 


116 


68.9 


62.6 


87.6 


74.9 


15 


94 


68.9 


62.4 


80.9 


75.0 


16 


75 


70.1 


65.8 


83.3 


78.8 


17 


56 


67.5 


62.7 


87.8 


81.2 



invariably so." Again, Winch contrasted six 13-year old girls, who stood 
between Number 1 and Number 11 in a class of 35, with 6 girls of the same age, 
who stood 25th to 30th in a class of 30, and found the average score of the 
bright girls to be 26.9, as compared with an average score of 19 for the dull 
girls (50, p. 133). 

Wessely believes that the correlation between memory and class standing 
is more evident in lower than in higher grades — a view which, if confirmed, 
might be explicable by the tendency to put a premium upon memorization 
in the lower grades. 

Meumann says that the quantity of material reproduced is not in itself 
a reliable index of intelligence, yet the average results of mass experiments 
will always show that the more intelligent S's have the better memory 
efficiency. His own experiments, he declares, were so extensive and so 
carefully executed as to leave no doubt at all upon this point (31, p. 78). 
More reliable, however, are the qualitative results attained from memory 
tests of the form used in his own experiments. Here, he says, virtually com- 



TEST 38: ROTE MEMORY 389 

plete coincidence is found between the several indexes of intelligence, and 
between them and the school marks and the estimate of mental ability by 
teachers. Certain characteristic indexes of poor intelligence, however, 
such as the fusion of abstract terms into meaningless collocations, may not 
be shown by all of the stupid children; if they are shown, they form a relia- 
ble index of poor intelligence, while if frequent, they indicate not only poor 
intelligence, but also the lack of moral qualities, such as self-control and 
carefulness. Incidentally, Meumann points out that, in theory, we should 
distinguish carefully between natural ability and actual ability as shown in 
school performance; in practise, nevertheless, these tend to coincide. 

(15) Memory of defectives. Galton (18) applied Jacobs' tests to 
imbeciles, and found that most *S's of this type failed to repeat 
more than 4 digits, while several imbeciles who had remarkable 
memories for dates or for passages in books showed complete 
failure (span not over 3) in memory for digits. Johnson (23) 
computes the average span for feeble-minded (selected *S's of the 
so-called 'school-case' group) at 5.3, or approximately 1.3 digits 
less than the normal span of an 8-year child. The distribution 
of efficiency, as he found it, is shown in Table 79. Johnson com- 
ments upon the fact that the difference between the memory span 

TABLE 79 
Memory Span for Digits in the Feeble-Minded {Johnson) 



Number of digits 

Repeated correctly by. 



3 
70 I 



6 I 7 
27 1 14 



Note — The larger groups include the smaller ones at their right. 

of the feeble-minded and of normal children seems to be of a smaller 
order than the general difference in intellectual ability of the two 
groups. 

Miss Norsworthy compared normal and feeble-minded children 
with respect to memory for related and for unrelated words. Her 
standards for normal children have already been reported (Table 
75) : the relation of feeble-minded to normal efficiency is shown in 
Table 80. The figures are to be interpreted simply: five per cent 
of the feeble-minded do as well with the related-word test as do 
50 per cent of normal children, etc. 

Smedley states "that the boys of the John Worthy School [in- 
corrigibles, defectives, truants, etc.] are lower in memory power 



390 



ASSOCIATION, LEARNING, AND MEMORY 



than are the pupils of the other schools, and this disparity in- 
creases mth age" (43, p. 59). 

Smith's tests with epileptics (46) show that, in the auditory 
letter-span test, they are generally inferior to normal S's, and in 
particular, that they make nearly three times as many errors of 
insertion. 



Comparative Memory Capacity of Normal and F eehle-Minded Children 
(Norsworthy) 



Normal (both tests) j 50 75 

Feeble-minded, in related words j 5 19 

Feeble-minded, in unrelated words ' 6 1 18 



(16) Other correlations. Krueger and Spearman found no cor- 
relation between memory for digits (serial visual exposure) and 
either ability to add, to discriminate pitch, or to discriminate dual 
cutaneous impressions. 

Memory for digits and memory for letters were correlated to a 
high degree in Miss Sharp's S's, while memory for short sentences 
correlated best with memory for letters. 

Smedley studied the relation of memory for digits and ability 
to spell, and concluded that ''while, on the whole, the good spellers 
have decidedly better memory power than the bad spellers, yet 
there are individuals among the poor spellers who are superior in 
memory power, and individuals among the best spellers whose mem- 
ory power is scarcely up to the average of their age. While this native 
power of sense memory plays an important role, it is by no means 
the only factor in learning to spell" (43, p. 61). 



TABLE 81 
Recall of Different Members of a 7-Term Series (Binet and Henri) 



Place in series j 1 

Times recalled correctly | 143 



2 
139 



3 

115 



4 
111 



5 
122 



117 



7 
140 



TEST 38: ROTE MEMORY 391 

(17) Miscellaneous observations, (a) Reproduction in correct 
order is more difficult than mere reproduction; reproduction is 
more difficult than recognition. 

(6) The first and the last terms of a series are more liable to be 
recalled than are the middle terms (Table 81). 

(c) In word tests, certain terms are often found to have a special 
reproducibility, evidently by attracting special attention in some 
way. Thus, Binet and Henri found that the word pupitre (desk), 
though in the middle of a series, and hence unfavorably placed, 
was recalled in an usually large number of cases. 

(d) Errors of omission are more common than errors of inser- 
tion or errors of substitution — in word tests with school children, 
4 times more frequent (Binet and Henri). 

(e) Wissler calls attention to the perseverative tendency men- 
tioned by Meumann and others: this is evinced by the introduc- 
tion, in the recall of a given series, of impressions that had been 
used in an earlier series. Wissler found this type of error especially 
common in college seniors and mature S's when trying the digit 
test. Meumann, it will be remembered, considered perseveration 
in the word test as an index of poor intelligence — when the S's 
knew that no series was like a previous one. 

REFERENCES 

(1) I. M. Bentley, The memory image and its qualitative fidelity, in A. J. 
P., 11:1899, 1-48. 

(2) J. A. Bergstrom, Experiments on physiological memory by means of 
the interference of associations, in A. J. P., 5: 1893, 356-369. See also An 
experimental study of some of the conditions of mental activity, ibid., 6: 
1894, 267-273, and Relation of the interference and the practise effect of an 
association, ibid., 6: 1894, 433-442. 

(3) J. A. Bergstrom, Effect of changes in the time variables in memorizing, 
together with some discussion of the technique of memory experimentation, 
in A. J. P., 18: 1907, 206-238. 

(4) A. Bernstein and T. Bogdanoff, Experimente liber das Verhalten der 
Merkfahigkeit bei Schulkindern, in Beitrage z. Psych, d. Aussage, 2: 1905, 
115-131. 

(5) A. Binet, Attention et adaptation, in A. P., 6: 1899 (1900), 248-404. 

(6) A. Binet, Introduction a la psychologie experimentale, Paris, 1894. 
Especially ch. V. 

(7) A. Binet and V. Henri, La memoire des mots, in A. P., 1: 1894 (1895), 
1-23. 



392 ASSOCIATION, LEARNING. AND MEMORY 

(8) A. Binet and V. Henri, La psychologic individuellc, in A. P., 2: 1895 
(1896), 411-465, especially 436-443. 

(9) T. L. Bolton, The growth of memory in school children, in A. J. P., 
4:1892,362-380. 

(10) B. Bourdon. Influence de I'lige sur la mcmoire immediate, in Revue 
philos., 38: 1894, 148-167. 

(11) W. H. Burnham, Memory historically and experimentally considered, 
in A. J. P., 2: 1S88-S9, 39-90, 225-270, 431-464, 568-622. 

(12) C. Burt, Experimental tests of general intelligence, in B. J. P., 3: 
1909, 94-177. 

(13) Alary W. Calkins, A study of immediate and of delayed recall of the 
concrete and of the verbal, in P. R., 5: 1898, 451-6. 

(14) J. Cohn, Experimentelle Untersuchungen fiber das Zusammenwirken 
des akustisch-motorischen u. des visuellen Gedachtnisses, in Z. P., 15: 
1897, 161-183. 

(15) H. Ebbinghaus, (a) Ueber eine neue Methode zur Priifung geistiger 
Fiihigkeiten in ihrer Amvendung bei Schulkindern, in Z. P., 13 : 1897, 401-457. 
(b) For review of the literature, see Grundzlige der Psychologie I, 2d ed. 
1905, 633-707. 

(16) E. Ebert and E. Meumann, Ueber einige Grundfragen der Psych, 
der Uebungsphiinomene im Bereiche des Gedachtnisses, in A. G. P., 4: 
1905, 1-232. 

(17) P. Eplu'ussi. E.xperimentelle Beitriige zur Lehre vom Gedachtnis, 
Berlin, 1906. Pp. 191. 

(18) F. Galton, Supplementary notes on 'prehension' in idiots, in Mind, 
12:1887,79-82. 

(19) Eleanor Gamble, A study in memorizing various materials by the 
reconstruction method, P. R. Mon. No. 43, Sept., 1909. Pp. 210. (Wellesley 
College Studies in Psychology, No. 1.) 

(20) C. J. Hawkins, Experiments on memory types, in P. R., 4: 1897, 289- 
294. 

(21) V. Henri, Education de la memoire, in A. P., 8: 1901 (1902), 1-48. 

(22) J. Jacobs, Experiments on 'prehension,' in Mind, 12: 1887, 75-9. 

(23) G. E. Johnson, Contribution to the psychology and pedagogy of 
feeble-minded children, in Pd. S., 3: 1895, 245-301, especially 268-273. 

(24) A. Jost, Die Associationsfestigkeit in ihrer Abhiingigkeit von der 
Verteilung der Wiederholungen, in Z. P., 14: 1897, 436-472. 

(25) F. Kemsies, Gedachtnisuntersuchungen an Schiilern, in Z.P. P., 2: 
1900, 21-30, 84-95. 

(26) E. A. Kirkpatrick, An experimental study of memorj^, in P. R., 1: 
1894, 602-9. 

(27) E. Kraepelin, Der psychologische Versuch in der Psychiatric, in P. 
A., 1: 1896, 1-91, especially pp. 73 ff. (See also G. Aschafifenburg, ibid., 
209-299.) 

(28) F. Krueger and C. Spearman, Die Korrelation zwischen verschiede- 
nen geistigen Leistungsfahigkeiten. in Z. P., 44: 1907, 50-114. 



TEST 38: ROTE MEMORY 393 

(29) J. Larguier des Bancels, Sur les methodes de memorisation, in A. P., 
8: 1901 (1902), 185-204. 

(30) M. Lobsien, Experimentelle Untersuchungen iiber die Gedachtniss- 
entwickelung bei Schulkindern, in Z. P., 27: 1901, 34-76. 

(31) E. Meumann, Intelligenzprufungen an Kindern der Volksschule, in 
E. P., 1:1905,35-101. 

(32) W. McDougall, On a new method for the study of concurrent mental 
operations and of mental fatigue, inB. J. P., 1: 1905, 435-445 ,*especially 436 f. 

(33) G. Miiller and A. Pilzecker, Experimentelle Beitrage zur Lehre vom 
Gedachtniss, in Z. P., Erganzungsband, 1 : 1900, 1-288. 

(34) G. Miiller and F. Schumann, Experimentelle Beitrage zur Unter- 
suchung des Gedachtnisses, in Z. P., 6: 1894, 81-190, 257-339. 

(35) A. Netschajeff, Experimentelle Untersuchungen iiber die Gedacht- 
nissentwickelung bei Schulkindern, in Z. P., 24: 1900, 321-351. 

(36) Naomi Norsworthy, The psychology of mentally deficient children 
(Columbia University thesis). New York, 1906. Pp. 111. 

(37) M. Offner, Das Gedachtnis, Berlin, 1909. Pp. 238. 

(38) A. Pohlmann, Experimentelle Beitrage zur Lehre vom Gedachtniss, 
Berlin, 1906. Pp.191. (For full review, see Z. P., 44: 1907, 134-140.) 

(39) F. Reuther, Beitrage zur Gedachtnisforschung, in Psych. Studien, 
1: 1906,4-101. 

(40) C. Ritter, Ermiidungsmessungen, in Z. P., 24: 1900, 401-444. 

(41) M.-C. Schuyten, Sur les methodes de mensuration de la fatigue des 
(5coliers, in Ar. P., 4: 1904, 113-128. 

(42) Stella E. Sharp, Individual psychology: a study in psychological 
method, in A. J. P., 10: 1899, 329-391. 

(43) F. Smedley, Report dept. child-study and pedagogic investigation, 
(Chicago Public Schools), No. 3, 1900-1901, also in U. S., 1902, i., 1115-1138. 

(44) W. G. Smith, The relation of attention to memory, in Mind, n. s. 4: 
1895, 47-73. 

(45) W. G. Smith, The place of repetition in memory, in P. R., 3: 1896, 
21-31. 

(46) W. G. Smith, A comparison of some mental and physical tests in 
their application to epileptic and to normal subjects, in B. J. P., 1: 1905, 
240-260. 

(47) E. B. Titchener, Experimental psychology. Vol. I., New York, 1901. 

(48) J. J. van Biervliet, L'education de la memoire a l'6Go\e, in Revue 
philos., 57: 1904, 569-586. 

(49) R. Wessely, Zur Frage des Auswendiglernens, in Neue Jahrbiicher 
f. Pjidagogik, 8: 1905, 297-309, 373-386. 

(50) W. H. Winch, Immediate memory in school children, in B. J. P., 1: 
1904, 127-134, and 2: 1906, 52-57. 

(51) W. H. Winch, The transfer of improvement in memory in school 
children, in B. J. P., 2: 1908, 284-293. 

(52) C. Wissler, The correlation of mental and physical tests, in P. R, M. S., 
3: 1901, No. 6. Pp.62. 



394 ASSOCIATION, LEARNING, AND MEMOEY 

TEST 39 

Memory for ideas : 'Logical' memory. — This test differs from 
the preceding tests of memory in two respects; in the first place, 
connected, meaningful material is used instead of a series of dis- 
parate impressions; in the second place, the reproduction that is 
demanded is primarily a reproduction of ideas, not an exact, ver- 
batim reproduction of the original presentation. In other words, 
this test, to use popular phraseology, measures 'logical,' instead 
of 'rote' memory. 

The purposes of the test are similar to those of other memory 
tests, viz:, to determine individual differences in memory effici- 
ency, as related to sex, age, training, native ability, etc. As in 
those tests, too, the effect of different methods of presenting the 
materia]^ or of different forms of material may be studied, and 
immediate may be compared with deferred reproduction. The 
results of the test may also be correlated with the results of other 
tests, particularly with the tests of rote memory just described. 



While, in principle, the attitude taken by S toward the test of memory 
for ideas is distinctly different from that taken toward the test of memory 
for discrete impressions, yet, in practise, it is not always possible to differ- 
entiate these attitudes in the tests as actually administered. Thus, Binet 
and Henri, and after them. Miss Sharp, conducted tests of "memory for 
sentences." In these tests, the sentences ranged from short to long, and 
from easy to difficult. A short, easy sentence, e.g., a sentence of 11 words, 
is almost invariably interpreted by S as a straightforward test of verbal 
memory, and the reproduction is at bottom a recall in verbal (mainlj^ audi- 
tory verbal) terms. On the other hand, a long, difficult sentence, e.g., a 
sentence of 86 words, when heard or read but once, must be reproduced in 
substance, not verbatim, and the recall, for most S's at least, is a recall 
by meaning, a reproduction of the 'gist' of the material presented. 

It is evidently better to keep separate these two different forms of memory 
test, with their two correspondingly different attitudes. The material of 
the present tests is, accordingly, sufficiently lengthy to preclude verbatim 
recall. Memory for sentences of progressive length may be studied by use 
of the sentences incorporated in the Binet-Simon tests of Chapter XIII. 



In addition to the work of Binet and Henri and of Sharp, exam- 
ples of the use of the logical-memory test may be found in Shaw's 



TEST 39: MEMORY FOR IDEAS 3P5 

study of memory in school children, in Wissler's records of the 
tests of Columbia freshmen, and in Terman's study of bright and 
dull boys. The most elaborate investigation of "memory for con- 
nected trains of thought" is, however, that of Henderson, who 
administered a series of tests to over 200 ^'s, ranging from 10-year 
old 5th-grade children to adult students in the university. Hen- 
derson's work forms the basis of the tests which are here prescribed, 
with some modifications suggested by the use of the test by the 
author for several years as a class exercise. 

Materials. — Watch. Three printed forms — The Marble 
Statue, Cicero, and The Dutch Homestead. 

The first of these is taken from the appendix of Shaw's article, and was 
apparently used by him for subsidiary tests. The second and third are 
Nos. 2 and 4 of the five texts used by Henderson. If E wishes to extend the 
test by using more difficult material, hemay employ Henderson's No. 5 — 
a selection entitled "The Stages in the Development of Human Theory," 
from Comte's Positive Philosophy. If the Marble Statue proves too difficult 
or uninteresting for very young ;S's, E may read to them the following 
(from Clyde and Wallace, Through the Year, Book 2, Silver, Burdett, and 
Company). 

How Mr. Lincoln Helped the Pig. 

"One day Mr. Lincoln was out riding. As he passed along the road, he 
saw a pig sinking into a mud-hole. Poor piggy would climb part way up 
the slippery bank, then down he would fall again. 

'I suppose I should get down and help that pig,' thought Mr. Lincoln. 
'But I have on my new suit, and it will be quite spoiled if I do so. I think 
I'll let him get out the best way he can.' 

He rode on. When nearly two miles away, he turned and came back. Not 
minding the new clothes, he stooped, and taking piggy in his arms, he 
dragged him out of the mud. 

The new suit was quite spoiled, but Mr. Lincoln said he had taken a pain 
out of his mind." 

Method. — Provide S with paper and pencil. Explain the nature 
of the test, as follows: "I am going to read you something to see 
how well you can remember it afterward. You must pay careful 
attention, as I shall read it but once. As soon as I have fin- 
ished, take your pencil and write as much of the story as you can 



396 ASSOCIATION, LEARNING, AND MEMORY 

remember. If you can remember it in just the words you heard, 
use those words, but if you can't do that, tell in your own words, 
as well as you can, what it was that I read to you." 

Read the passage, including the title, with most careful enuncia- 
tion, and with proper attention to expression. The rate of reading 
should be somewhat slower than in ordinary reading — say a full 
minute for the Cicero text. Allow *S ample time for writing, then 
ask him to underline each word in his reproduction that he feels 
sure is exactly the same as the original passage.^ 

Variations of Method. — (1) Supply aS with the printed text. 
Inform him that he is to have 3 min. to read the passage. Assure 
him that this time is ample to read it over carefully several times. 
Direct him to read the passage straight through twice, and then 
to commit it to memory as he wishes. 

(2) Defer the reproduction to any desired time after the reading, 
e.g., 10 min., 24 hours, 1 week, 4 weeks. Or require an immediate 
reproduction, followed later, at one or more of the intervals 
just suggested, by a second or by a third reproduction.^ Conduct 
these deferred trials in the same manner, as far as directions to 
underline, etc., are concerned, as in the first trial. 

Treatment of Data. — The simplest plan for scoring the data 
of this test is that used by Terman and by Wissler, who merely 
graded the papers on a scale of 5 (or of 10) for a perfect reproduc- 
tion — perfect in the sense of a reproduction of all the ideas of the 
original text, whether in terms identical with, or merely equiva- 
lent to the original. 

For ordinary purposes, the author has found it serviceable to 

1 This test lends itself easily to the group method. The usual precautions 
should be taken to avoid disturbance and communication. E may save him- 
self much labor by asking each S to count the total number of words he has 
written, then the total number of words he has underlined. With mature 
S's, E may also reread very slowly the original text, and let each S check up 
the total number of ideas correctly reproduced, i.e., represented, whether 
verbatim or by equivalent phrases, in his reproduction. The division of 
each text into its constituent 'ideas' is indicated below. 

2 It is better, on the whole, to give no intimation of the intent to demand a 
second reproduction. Some S's may compare notes after the first reproduc- 
tion, but if the subsequent trial is announced beforehand, coupled, as it 
ought to be, with the request not to think of the test in the interim, the re- 
quest is more apt to work as a counter-suggestion, so that many S's will 
test their recall of the passage, and otherwise furbish up the memories dur- 
ing the interval. 



TEST 39: MEMORY FOR IDEAS 379 

score the papers for the following points: (1) number of words 
written, (2) number of words underlined, (3) percentage of under- 
lined words that are correctly underlined, (4) number of ideas 
(' details' in Henderson's terminology) that have been reproduced, 
whether exactly or in equivalent phrases. To these may be added, 
if desired, (5) number of ideas wrongly inserted. If but a single 
score is to be made, the fourth is obviously the one to be used, 
since the task assigned to S is to give as many as possible of the 
ideas of the text.^ 

The second and subsequent reproductions are scored in the same 
manner as the first. Retention is then measured, following Shaw 
and Henderson, by computing the percentage of loss between these 
and the first reproduction. Occasional cases of improvement in 
the later reproductions are rated as a zero loss. 

To ascertain the ' idea-score,' *S's reproduction must be compared, 
step by step, with the standard divisions of the original text into 
ideas. 2 

The Marble Statue 

(166 words, 67 ideas) 

A. young ] man \ worked | years ] to carve | a white j marble | 
statue I of a beautiful \ girl. | She grew prettier | day by day.| 
He began to love the statue ] so well that \ one day \ he said to 
it: 1 "I would give ] everything | in the world | if you would be 
alive I and be my wife."| Just then | the clock struck | twelve, ] and 
the cold 1 stone began to grow warm, \ the cheeks red, | the hair 
brown, | the lips to move.j She stepped down, | and he had his 
wish. I They lived happily \ together | for years, ] and three | beauti- 
ful 1 children were born.] One day j he was very tired, \ and grew] 
so angry, ] without cause, | that he struck her.| She wept, ] 
kissed | each child 1 and her husband, | stepped back j upon the 
pedestal, ] and slowly ] grew cold, | pale \ and stiff, | closed her eyes, | 

1 Consult Sharp or Henderson for more elaborate methods of treating 
data, particularly for devices for qualitative analysis. 

^ The scoring for ideas for these three passages is taken, with a few minor 
changes, from Shaw and from Henderson. For a division of the second and 
third texts into topics and sub-topics as well as into ideas, the reader may 
consult Henderson (2, pp. 29-30). 



398 ASSOCIATION, LEARNING, AND MEMORY 

and when the clock | struck ] midnight, \ she was a statue j of pure | 
white I marble | as she had been ] years before, \ and could not 
hear | the sobs | of her husband | and children. 

Cicero 

(125 words, 65 ideas) 

"Cicero, ] the greatest | of the Roman ] orators, | was born 1 at 
Arpinum, | an obscure | country | town.j His family | was of the 
middle class ] only, | and without wealth, | yet he rose ] rapidly | 
through the ranks ] of Roman \ official service | until at the age \ 
of fort/-six 1 he became | consul. 1 In oratory | he is ] by universal 
consent [ placed side by side ] with Demosthenes, | or at least | 
close after him. | He surpassed \ the great | Attic \ orator | in 
brilliancy | and variety, ] but lacked | his moral \ earnestness \ and 
consequent [ impressiveness-l He could be | humorous,] sarcastic, \ 
pathetic, j ironical, | satirical, \ and when he was malignant | his 
mouth was | most j foul | and his bite 1 most | venomous. | His 
dehvery | was impassioned | and fiery, | his voice ] strong, | full, | 
and sweet, | his figure | tall, ] graceful, | and impressive." 

The Dutch Homestead 

(180 words, 91 ideas) 

"It was I one 1 of those spacious j farm- ] houses, 1 with high- 1 
ridged, 1 but lowly ] sloping 1 roofs, j built ] in the style | handed 
down from | the first | Dutch [ settlers, \ the low j projecting! eaves j 
forming a piazza | along the front | capable 1 of being closed up \ 
in bad weather. \ Under this | were hung j flails, | harness, j vari- 
ous 1 utensils \ of husbandry, | and nets | for fishing \ in the neigh- 
boring 1 river. | Benches | were built 1 along the side | for summer 
use ; 1 and a great \ spinning wheel | at one end, ] and a churn j at 
the other, | showed | the various 1 uses | to which this important | 
porch 1 might be devoted. 1 From this piazza ] one might enter | 
the hall, | which formed ] the center ] of the mansion ] and the usual] 
place of residence. \ Here | rows \ of resplendent [ pewter ] 
ranged \ on a long | dresser [ dazzled [ his eyes. ] In one cor- 
ner I stood a huge | bag \ of wool,] ready \ to be spun; ) in another ] 



TEBT 3P: MEMORY FOR IDEAS 



H99 



a quantity 1 of linsey-woolsey, 1 just ] from the loom; ] ears | of 
Indian \ corn | and strings | of dried | apples | and peaches j hung 1 
in gay j festoons | along the walls, | mingled 1 with the gaud ] of 
red 1 peppers." 

Results. — (1) Individual differences in memory for ideas are 
unexpectedly large, even within a group of >S"s of apparently similar 
attainments (Table 82). 

(2) Sex differences in this test, as in the rote-memory test, are 
in favor of girls. The difference is indicated clearly in the author's 

TABLE 82 

Old Homestead Test. Words Wrillen and Underlined {Whipple) 



KinST TRIAL, NO INTERVAL SECOND TRIAL, 24 HOURS LATER 



fotal Words 



Words Under- 
lined 



Words Under- 
lined 



AvcraKcOmen 80.4 48.0 83.0 38,4 

A vera^c, 22 women 95 . .5 38 , 8 09 34 1 

Maximal records 127.0 102.0 138.0 66.0 

Minimal records 45.0 i 4.0 i 52.0 9.0 



data for college students (Table 82), and similar differences are 
reported by Shaw, who found the growth of memory for ideas to 
be faster in girls than in boys, and the average performance of 
girls to l)c some 4 per cent better than that of boys. Wissler's 
records f(;r Columbia freshmen show an average of 44.5 per cent, 
P. E. 11 . 1 , for men, and 48.2 per cent, P. E., 13.2, for women. 

(3) Aqe. Binet and Henri state simply that, in the test with 
long sentences, the number of words retained is related to age. 
The more elaborate studies of Shaw and of Henderson are some- 
what difficult to interpret. It appears evident, however, that a 
distinction must be made between efficiency in the first reproduc- 
tion and efficiency in subsequent reproductions. If the first be 
termed learning capacity, and the second retentive capacity, and 
if the latter be measured in terms of the proportion of the first 
reproduction that is retained in the second (or later) reproduction, 
then adults may be shown to surpass children in learning capacity, 
but not in retentive capacity. 



400 ASSOCIATION, LEARNING, AND MEMORY 

Thus, in Shaw's rather difficult 324-word story, the learning 
capacity of boys increased, from the 3d to the 9th grade, from 17 
to 42 per cent, that of girls from 18 to 43 per cent. High-school 
boys averaged only 40 per cent, high-school girls about 47 per 
cent. Shaw's university students did no better, while Henderson's 
summer session students were inferior to his 15 and 16-year old 
school children. In short, then, logical, like rote memory, appears,, 
when measured by the first reproduction, to be at its best near 
puberty. 

Turning to the later reproductions, Shaw and Henderson 
(Table 83) agree that younger S's have as good retentive capacity 
as do adults. 



Average Percentage of Loss in Third Reproduction ( 
(Henderson) 


After 


4 Weeks) 


AGE 


ADULTS 16 15 14 13 


12 


11 


10 


Percentage of loss. . . . 


14 8 13 15 


14 


12 


10 


10 



(4) Time-interval. The insertion of a time-interval between 
presentation and reproduction has much less effect upon memory 
for ideas than upon memory for discrete impressions. Table 82 
shows that, if a second reproduction is called for one day after the 
first, the average S actually writes more words. The words in 
the later reproduction are, however, less exact copies of the original 
text, and there is a tendency to insert extraneous material, so that 
fewer words are underlined, and there is a slight net reduction in 
the number of ideas reproduced. In the author's tests, this reduc- 
tion was but 3 per cent at the end of one week. Table 83 shows 
that an interval of 4 weeks produces a loss of but 8 to 15 per cent. 

It is a matter of special interest to note that the relative standing 
of S's remains practically identical in tests conducted with immedi- 
ate, and with deferred reproduction. It follows that, so far as this- 
test goes at least, the popular notion ''easy come, easy go" is not 
borne out by experimental evidence. Henderson found that this 
correlation between learning capacity and retentive capacity was 
brought out better in scoring for ideas than in scoring for words. 



TEST 39: MEMORY FOR IDEAS 401 

(5) Dependence on method of presentation. When a single 
hearing is compared with reading done by S (3 min.), the former is 
found to be nearly as good as the latter for immediate reproduc- 
tion, but the latter to be much more effective than the former for 
deferred reproduction. 

(6) Dependence on practise. There is little doubt that practise 
will improve memory for ideas, as it will improve nearly every form 
of psychophysical activity. Special training thus accounts, in all 
probability, for the high scores (52 as over against 40 to 47 per 
cent) reached by the pupils of Miss Aiken's schooP in comparison 
with the work of Worcester high-school children. 

(7) Dependence on length of text. The number of words repro- 
duced after one hearing increases, though not in direct propor- 
tion, with the length of the passage heard (Binet and Henri). 

(8) Dependence on portion of text. If the original passage be 
divided into 3ds or 4ths (or even, if long, into 8ths), it will be found 
that, on the average, the reproduction of any one of these portions 
is inferior to the one that precedes it and superior to the one that 
follows it. Thus, Shaw's story, on division into 4 parts, was found 
to be reproduced in the amounts 52, 34, 31, and 28 per cent, 
respectively. 

(9) Uniformitij. If several texts are used with the same group 
of S's, their standing in the several trials shows a high degree of 
correlation. The test may, therefore, be regarded as having a 
good degree of reliability. 

(10) Relation with school sta7iding. In 86 cases, Wissler found 
a correlation of 0.19 with class standing, of 0.11 with standing in 
mathematics, and of 0.22 with standing in Latin. Henderson found 
but a slight correlation with class standing in the lower grades, 
but a closer correlation in the higher grades. He is of the opinion 
that, at least in the lower grades, the school marks put a premium 
upon industry and good conduct, rather than upon native ability, 
and thus obscure the existing correlation. 

(11) Other correlations. Wissler found a correlation of 0.21 
between logical memory and length of head, but no correlation 
between logical memory and rote memory, speed of naming colors, 
reaction time, or breadth of head. 

1 For an account of the special training given to Miss Aiken's pupils, see 
Test 25 and references thereto. 



402 ASSOCIATION, LEARNING, AND MEMORY 

(12) Qualitative aspects. Inspection of the work of children and 
introspective examination by adults of their own mental processes 
reveal a number of interesting principles. In the first place, there 
is a process of selection: words or ideas that are logically or psycho- 
logically important are best retained. Or, as Henderson expresses 
it, there is, especially during a long time-interval, a process of 
condensation and generalization. The main ideas, the important 
topics, the brunt of the passage maj- remain fairly constant, but 
the minor details tend to be forgotten, and the original phrasing 
to become less and less clear. 

When, then, the reproduction is demanded, most >S's first recall 
these main ideas or larger topics, and then develop the details, as 
best they may, from them. There is a strong tendency, in this 
filling out of the details, toward what Binet and Henri speak of 
as "verbal assimilation," i.e., a tendency to express the ideas in 
one's own terms, rather than in those employed in the original 
passage. Thus, adults often use synonyms or other forms of 
substitution, while children replace the words of the original 
by words from their ordinar}^ vocabulary (e.g., played for amused 
themselves, fire for conflagration), and at the same time tend to 
simplify the syntax. In general, Binet and Henri found that the 
number of times that synonyms are used in the recall is, in short 
passages greater, and in long passages less than the number of 
ideas completely' omitted. 

Finally, the substitution of terms for those of the original tends, 
especially in younger aS's and with longer time-intervals, to become 
inexact ; in other words, the sense of the original becomes more or 
less distorted. Thus, for instance, Binet and Henri discovered 
that, in all sentences containing more than 20 words, more than 
half of their /S's had made some change in the meaning of the 
original. Of these alterations of sense, the most conspicuous are: 
(1) change of proper names or of numbers, (2) replacement of 
an object by an analogous object that might fit the sentence equally 
well, (3) insertion of details not inconsistent with the original, 
but still not in the original, and (4) alterations apparently due to 
emotional reaction, especially to exaggeration, e.g., a frightful 
snake for a snake. 



TEST 39: MEMORY FOR IDEAS 403 

(13) Miscellaneous points. In the case of college students, from 
50 to 90 per cent of the words underlined are actually correct. A 
certain t^T^e of >S may be recognized, who is extremely cautious 
about underlining words, but who usually has these few nearly all 
correct.^ 

Binet and Henri estimate that memory for connected sentences 
is approximately 25 times as good as memory for discrete terms. 

REFERENCES 

(1) A. Binet and V. Henri, La memoire des phrases, in A. P., 1: 1894 
(1895), 24^59. 

(2) E. N. Henderson, A study of memory for connected trains of thought. 
New York. Pp.94. (Columbia University thesis.) 

(3) Stella E. Sharp, Individual psychology: a study in psychological 
method, in A. J. P., 10: 1899, 329-391. 

(4) J. C. Shaw, A test of memory in school children, in Pd. S., 4: 1896, Ql- 
78. 

(5) L. W. Terman, Genius and stupidity, in Pd.S., 13: 1906, 307-373. 

(6) C. Wissler, The correlation of mental and physical tests, in P.R.M.S., 
3: 1901, No. 16. Pp. 62. 



Cf . the type of cautious reporter mentioned in Test 32. p. 304. 



CHAPTER X 

Tests of Suggestibility 

The term 'suggestion' has found different usages in psycliology. 
Four different usages at least may be distinguished. (1) Sugges- 
tion is equivalent to association, e.g., the idea 'horse' suggests 
the idea 'Black Beauty.' (2) Suggestion is the conveyance of 
an idea by hint, intimation, or insinuation, e.g., the orator sug- 
gests an idea by an appropriate gesture. (3) Suggestion is a 
method of creating and controlling hypnosis. (4) Suggestion is a 
process of creating belief or affecting judgment, usually an er- 
roneous belief or false judgment, in the normal consciousness. 

The tests which follow all purport to measure susceptibility to 
suggestion in this last-named sense. In them, the experimenter 
seeks, bj suitable arrangement of the test-material or of the in- 
structions, to induce the subject to judge otherwise than he nat- 
urally would — to induce him, for example, to judge equal liries 
or equal weights to be unequal, or to perceive warmth when there 
is no warmth, etc. If the attempt is successful, the subject is said 
to have 'yielded,' or to have 'accepted' the suggestion; if unsuc- 
cessful, he is said to haye 'resisted' the suggestion. The degree of 
his suggestibihtj' is indicated by the quickness or frequency of 
his 'yields.' 

Just as efficiency in observation, attention, memory, and the like 
has been shown to be specific, not general in character, so is it prob- 
able that suggestibility is specific, not general in character. For 
this reason, suggestibility nmst be tested by more than one method. 

Many of the tests in other portions of this book, e.g., Nos. 17 
and 23, afford opportunity for noting the suggestibility of sub- 
jects. The serial graded tests of Binet and Simon (Chapter XIII) 
also contain directions for testing the suggestibility of young or 
of feeble-minded children. 



TEST 40: SIZE-WEIGHT ILLUSION 405 

TEST 40 

Suggestion by the size- weight illusion. — Big things are ordi- 
narily heavier than small things of the same kind. When we lift 
two weights of apparently the same material, but of different sizes, 
we more or less unconsciously put forth more energy or expect to 
meet with more resistance in lifting the larger. If, as in the case 
of the so-called 'suggestion-blocks,' the weights are really the same, 
we almost inevitably judge the larger weight to be the lighter; in 
other words, the visual app'earance of the weight has given us a 
suggestion — or, as it turns out, rather, a disappointed suggestion, 
— of weight.^ 

This error of judgment is undoubtedly due to an association 
built up by long experience in handling and lifting various articles 
and objects.^ One might, therefore, suppose that younger chil- 
dren, or less intelligent children, who would, presumably, have had 
less of this discriminative association of size and weight, would be 
less affected by the suggestion. For this reason, the size- weight 
test has been applied by several investigators to determine or to 
measure, at least relatively, the degree of suggestibility exhibited 
by school children under various conditions. 

Apparatus. — -Low table. Soft black cloth. Set of 'suggestion- 
blocks,' patterned after Gilbert, but modified by extending the com- 
parison series in both directions. 

This set consists of two standard blocks and 20 comparison blocks. Both 
standards weigh 55 grams; both are 28 mm. thick, but the larger is 82 and 
the smaller 22 mm. in diameter. The 20 comparison blocks are all 28 mm. 
thick and 35 mm. in diameter, but their weights range from 5 to 100 g. by 
5 g. increments.^ All are painted dead black. 



^ As Scripture remarks, the poor fallow who has been laughed at for cen- 
turies for saying that a pound of lead is heavier than a pound of feathers is 
perfectly right, so long as he speaks psychologically, and looks at the 
pillow and the bit of lead pipe. A concrete demonstration of the truth of 
this statement is afforded by several experiments reported by Wolfe. 

^ Some writers, however, e.g., Flournoy, attribute the illusion to an inborn 
nervous connection. For a discussion of the psychological factors concerned 
in this experiment, particularly in its relation to the 'innervation-sense,' 
consult Flournoy, Miiller and Schumann, Seashore, Bolton, Loomis, and 
van Biervliet. 

* Gilbert's comparison blocks were but 14 in number, with a range from 
15 to 80 g. This range proved inadequate for younger S's. 



406 SUGGESTIBILITY 

Method. — Arrange the table at such a height that S's forearm 
will be parallel with the floor when lifting a weight. Spread the 
black cloth over the table: this cloth should be large enough to 
cover at least the portion of the table occupied by the weights, 
and thick enough to deaden the sounds incident to their replace- 
ment. 

Arrange the twenty comparison blocks on the cloth, in the order 
of their weight from left to right, and in such a manner that any 
one of them may be reached by >S without materially changing 
the angle of his arm. Place before S the larger standard block, 
and say: "Here is a block. I want you to find a block in this series 
of 20 blocks that seems to you just as heavy as this one. Lift it 
by picking it up edgewise with your thumb and finger, like this. 
[Illustrate.] Then try the first of these weights [at the left]. If 
that doesn't suit, try the next, then the third, and so on, till you 
find a block that seems equal to this one. Each time you must 
lift this block first, then the one you are trying in the series. 
Keep your eyes constantly directed at the weight you are lifting." 
When S has selected an equivalent weight, the same procedure is 
followed with the second, or smaller, standard block. 

Our estimate of the absolute or relative weight of a body is conditioned 
by an unsuspectedly large number of factors, the analj^sis of which has been 
the occasion of a number of extended and carefullj'-executed researches. i 
While space forbids a discussion of these factors here, it should be impressed 
upon E that the conditions under which S lifts the blocks should be kept as 
uniform as possible. Particularly, since the apparent weight of a body de- 
pends in part upon the velocity and height to which it is lifted, it is im- 
portant that S should pick up each block in the same manner, lift it at the 
same tempo and to the same height. Again, since the memory image for 
weight changes rapidly, »S's judgment, in so far as it is based upon the 
image of the first weight, would be appreciably altered if the second weight 
were lifted at varying intervals after the first: the interval should, 
accordingly, be made as constant as possible, and fairly short, say not over 
3 sec, and the arrangement of the weights must be such as to permit this 
procedure. Finally, in this test, since the suggestion hinges upon the 
visual perception of the block, E must be sure that S looks directly at each 
block as he lifts it. 



See particularly, Martin and Mliller, and Miiller and Schumann. 



TEST 40: SIZK-WEIGHT ILLUSION 407 

Treatment of Data. — Following Gilbert, Scripture, and Sea- 
shore, the force of suggestion produced by the difference in size of 
the two standard blocks may be indicated by the difference in 
weight, in grams, between the two comparison blocks that are 
selected by S as the equivalents of the two standards. 

The force of the size-weight illusion has been expressed by Scrip- 
ture, on the basis of the more elaborate suggestion-blocks used by 
Seashore, in the form of the following law: 

i = - d, 

s-fc 

in which 

i = the amount of the illusion, 
s = the difference in size acting as a suggestion, 
c = the diameter of the blocks of constant size, 
d = the weight of the blocks of constant weight, and 
A; = a constant depending on the nature of the experiment 
(whether the blocks arc directly observed, whether 
S knows the nature of the illusion, etc.).^ 

Results. — (1 ) The effect of age upon suggestibility by the size- 
weight illusion is judged by Dresslar, who employed another and 
less satisfactory method, to be indifferent. Gilbert, however, found, 
as Table 84 indicates, that the illusion is strong at 6, increases 
gradually till 9, and thence declines with age. 

(2) The relation of sex to suggestion by the size-weight illusion 
has been differently stated by different investigators. Dresslar, 
for example, concludes that boys are more suggestible than girls. 
Wolfe, on the contrary, states that "men are less prone than 
women to illusions of weight," and that, in comparing wooden 
with lead weights, ''the women overestimate the lead nearly twice 
as much as the men." Gilbert and Seashore find females more 
suggestible than males, but in nothing like the degree stated by 
Wolfe. Thus, inspection of Table 84 shows that, according to 

' For the data from which this law is derived, see Scripture (15,- p. 276 f.), 
also Seashore (11, pp. 3-14). For a striking demonstration of the force of 
the illusion, reference may be made to Wolfe's statements that "about one 
woman in 7 finds 1 g. of lead equal in weight to 60 g. of inflated paper bag," 
and not " one woman in 7 will find a gram of inflated paper bag half as heavy 
as a gram of lead" (p. 460). 



408 



SUGGESTIBILITY 



Gilbert's method, girls are, after the age of 9, on the average, more 
influenced by the illusion than are boys. Seashore (12) tested 17 
women and 28 men with two test-weights quite different in size, 
and found, similarly, that on the average the women showed the 
stronger illusion. 

TABLE 84 

Force of Suggestion (Gilbert) 



.OK 


6 7 


8 1 9 


10 


11 12 13 


14 15 16 17 


NB 


45 50 


46 I47 


49 


43 54 45 


47 49 47 43 


NG 


47 145 


46 


47 


42 


48 49 ! 58 


53 51 39 41 


F 


42.0 ; 45.0 


47.5 


50.0 


43.5 


40.0 40.5 1 38.0 


34.5 35.0 34.5 27.0 


P 


36 37 


27 


36 


23 


22 15 8 


7 12 6 1 5 


MV 


17.0 ! 15.5 


13.5 10.5 


12.5 


11.5 9.0 9.0! 9.5 10.5 10.0 12.0 


FB 


43.5 43.5 


45.0 50.0 i 40.0 38.5 38.0 37.0 31.0 33.0 32.0 25.0 


FG 


42.0 43.5 


49.5 49.5 44.0 40.0 41.0 38.0 33.5 38.0 38.5 31.0 



NB = number of boys 

NG = number of girls 

F = force of suggestion, in grams, for both sexes (median values) 

FB = force of suggestion, in grams for boys (median values) 

FG = force of suggestion, in grams, for girls (median values) 

P = per cent, of cases in which F exceeded 65 g., the limit used 

MV = statistical mean variation 



Gilbert's explanation is given in the following terms: "At 6 he has not 
yet learned to compare. As he learns gradually to judge a thing from more 
aspects than one, or in other words, learns to interpret one sense by another, 
the force of suggestion given by the eye to the muscle increases until at 
9 he has come to the age of experience enough to see that things are not 
always what they seem. Consequently at this age he begins to correct mis- 
leading influences bearing upon him." 



(3) Practise, even if regular and persistent, does not dispel the 
illusion. If S be told the nature of the illusion, it still persists, 
though its intensity is thereby somewhat reduced (Seashore) . 

(4) The relation of intelligence to suggestibility has not been 
treated as carefully as the problem warrants. Gilbert made no 
correlations with intelligence. Dresslar concluded that bright 
children exhibit a stronger illusion, but Seashore (11) contends 



TEST 40: SIZE-WEIGHT ILLUSION 409 

that Dresslar's method (arrangement in serial order) did not afford 
a real measure of the strength of the illusion. 

(5) If the method of procedure be modified, the strength of the 
illusion will be altered. 

The more important of the relations tlius revealed are the following :i 

(a) "The illusion of weight dependent on size is greatest when size is 
estimated mainly by muscle-sense, and the weights have not previously 
been seen." 

(6) "The illusion is more fluctuating and on the whole not quite so strong 
when size is estimated by the area of pressure in the flat palm, including a 
memory of the third dimension." 

(c) "In these variations, the illusion is weakest when size is estimated 
by direct sight." 

(d) "When size is estimated by the combined effect of all the spatial 
senses, the illusion is weaker than when depending on muscle-sense or touch, 
and stronger than when dependent on sight alone." 

(e) The illusion is weaker when the blocks are viewed in indirect vision, 
and still weaker when judged by visual memory. 

(/) A knowledge, or supposed knowledge, of the material of which 
weights are made may affect the estimate of their weight. 

(g) The illusion does not necessarily vary directly with the volume of the 
compared weights, but depends in part upon the manner in which the differ- 
ence in volume is brought about. 

(h) The illusion obtains among the blind, where it follows the same gen- 
eral law as for the seeing, though it is not so strong, either for lifted or merely 
'touched' weights, as for the seeing under the same conditions (Rice). 

Notes. — The outcome of any test of weight-comparison is some- 
what affected by the tendency felt by all S's, though differing in 
degree between different individuals and in the same individual 
at different times, to overestimate the second of two lifted weights. 

If blocks of different material, e.g., cork and lead, or wood and 
iron, be constructed in such a manner as to have the same dimen- 
sions and the same weight, the knowledge of the actual differences 
in the weight of the two materials produces an illusion similar to 
the size-weight illusion. Seashore (12) tested school children with 
this material-weight illusion, and found that the overestimation 
of the metal blocks amounted to from 7 to 11 grams (or from 13 
to 20 per cent of their actual weight, 55 g.). For this illusion, it 

' See, especially. Seashore (11). 



410 SUGGESTIBILITY 

is of interest to note, there was found virtually no variation with 
age, sex, or intellectual abihty. 

REFERENCES 

^ (1) F. E. Bolton, A contribution to the study of illusions, etc., in A. J. P., 
9: 1898, 167-182, especially 167-178. 

(2) A. Charpentier, Analyse experimentale de quelques elements de la 
sensation de poids, in Archives de physiologie normale et pathologique, 
5th ser., 3: 1891, 122-135, especially 126 ff. 

(3) F. B. Dresslar, Studies in the psychology of touch, in A. J. P., 6:1894, 
313-368, especially 343-360. 

(4) Th. Flournoy, De I'infiuence de la perception visuelle des corps sur 
leur poids apparent, in A. P., 1: 1894 (1895), 198-208. 

(5) J. A. Gilbert, Researches on the mental and physical development 
of school children, in Y. S., 2: 1894, 40-100, especially 43-5, and 59-63. i 

(6) H. N. Loomis, Reactions to equal weights of unequal size, in Y. S., 
n. s. 1: No. 2, June, 1907, 334-348. (Same as P. R. M. S., 8: No. 3, whole 
No. 34.) 

(7) L. Martin and G. E. Miiller, Zur Analyse der Unterschiedsempfind- 
lichkeit, Leipzig, 1899. Pp. 233. 

(8) G. E. Miiller and F. Schumann, Ueber die psychologischen Grund- 
lagen der Vergleichung gehobener Gewichte, in Archiv f. d. ges. Physiol., 
45:1889,37-112. 

(9) J. Philippe and J. Claviere, Sur une illusion muscidaire, in Revue 
philos., 40: 1895, 672-682. 

(10) J. F. Rice, The size-weight illusion among the blind, in Y. S., 5: 
1897, 81-7. 

(11) C. E. Seashore, Measurements of illusions and iiallucinations in 
normal life, in Y. S., 3 : 1895, 1-67, especially 1-29. 

^ (12) C. E. Seashore, The material-weight illusion, in I. S., 2: 1899, 36-46. 
(13) E. W. Scripture, Remarks on Dr. Gilbert's article, in Y. S., 2: 1894, 

101-4. 
(14) E. W. Scripture, The law of size-weight suggestion, in Science, n. s. 

5:Feb. 5, 1896, 227. 

(15) E. W. Scripture, The New Psychology, London, 1897. See ch. xix. 

(16) J. van Biervliet, La mesure des illusions de poids, in A. P., 2: 1895, 
79-86. 

(17) H. K. Wolfe, Some effects of size on judgments of weight, in P. R., 
5: 1898, 25-54. 

TEST 41 

Suggestion by progressive weights. — ^This test, like that which 
follows it, is one of several devised by Binet for the purpose of 



TEST 41: PROGRESSIVE WEIGHTS 411 

securing a quantitative measure of the degree of suggestibility of 
children or adults when the suggestion is 'depersonalized/ in the 
sense that it is derived by S himself from the objective conditions 
of the experiment, rather than from the attitude, tone, instruc- 
tions, or personality of E. The principle embodied in this test is, 
in other words, the arousal, by auto-suggestion, of a "directive 
idea," or the rapid development of an attitude of expectation. 
Suggestibility is measured, at least approximately, by the ease with 
which this suggestion, or hq,bit of judgment, is aroused and by the 
persistence that it displays under conditions which tend gradually 
to counteract it. 

Materials. — Asetof 15weights,of identical size and appearance, 
numbered conspicuously from 1 to 15. The first four weigh 20, 40, 
60, ancl 80 grams, respectively; the remaining 11 weigh 100 grams 
each. Table of such a height that S can stand in front of it and 
lift the weights readily. A thick gray or black cloth. 

Preliminaries.^ — Spread the cloth over the table. Place the 
15 weights on it in a Hne, with the lightest on the left and the 11 
heaviest on the right, and with about 2 cm. between each weight. 
No. 1 is then at the left, No. 15 at the right, of the row. 

Method. — Give S the following instructions: "Here is a series 
of weights, 15 of them. I want you to lift them, one after the other, 
like this. [Illustrate by taking a weight between thumb and finger 
and lifting some 10 cm. from the table.] As you lift each weight, 
I want you to tell me whether it is heavier, lighter, or the same as 
the one just before it. All you have to say is either 'heavier,' or 
'lighter,' or 'the same.' Remember y^u are to compare each 
weight with the one you lifted just before. For instance, when 
3/0U lift the 8th, you are to say whether it is heavier, hghter, or 
the same as the 7th. Here is the first weight, number one, at the 
lelt end of the row." 

Watch *S to see that he follows these instructions, particularly 
that he lifts the weights successively, without relifting earlier ones. 
Record his judgments verbatim; be careful, also, to note any sec- 
ondary evidences that might throw light on his judgments, e.g., 
attitudes or expressions of hesitancy, assurance, surprise, embar- 
rassment, cautiousness, etc. 

Variations op Method. — (1) Inthesecond method followed by 



41 2 SUGGESTIBILITY 

Binet, S is instructed to lift, in each trial, the preceding weight 
as well as the one that is being judged, e.g., he lifts the 8th, then 
the 7th, then the 8th again: next the 9th, then the 8th, then the 
9th again, etc. The lifting is all done, as before, with the one hand. 

(2) In the third method followed by Binet, S is asked to estimate 
the first weight lifted . He usually gives too small an estimate. He 
is then told that its weight is 20 grams (about 0.7 ounce). The 
series is now compared, using either of the methods of lifting 
above described, according to S's preference,^ but ;S is required to 
estimate or guess the heaviness of each weight, basing his judgment, 
of course, merely on the knowledge that the first weight is 20 grams. 

Treatment of Data. — From the tabulated results, £" may easily 
determine in how many cases the objective progression of the first 
5 weights was correctly noted. For a measure of suggestibility, 
E must take the number of times 'heavier' is judged in the last 10 
judgments (when 'same' is the correct judgment). This measure 
is admittedly somewhat crude, but it affords a fairly reliable index 
for determining the relative order of rank of a group of S's. Thus, 
an S that judges 'heavier' 10 times is unquestionably more sug- 
gestible than one who answers 'heavier' but 5 times, though not 
necessarily twice as suggestible. 

If all three methods are employed, E may determine S's sugges- 
tibility b}'' adding the number of false 'heavier' judgments in all 
three tests. In the third method, the quantitative estimate given 
by S for the 15th weight (or the maximal estimate for weights 6 to 
15) might be taken, in comparison with his estimate of the 5th 
weight, as an index of suggestibility, but this method is not re- 
garded by Binet as so reliable as the one already described. 

Results. — (1) The general outcome of the test as conducted 
by the first, or standard, method is indicated in Table 85, which 
embodies the results obtained by Binet upon 24 elementary-school 
children, aged 8-10 years. 

(2) It is evident that, in children of this age (8-10), not all judge 
correctly the actual objective increase in the first five weights. 
Since the differences are supraliminal, the exceptions must be 

1 It would, obviously, be better to prescribe either the one or the other 
method for all S's. The first method has the merit of taking less time, and 
it is the method that is for the most part naturally adopted by younger S's. 



TEST 41: PROGRESSIVE WEIGHTS 



413 



TABLE 85 

The Progressive-Weight Suggestion. 24 Cases (Binet) 



NO. OF WEIGHT 

Actual weight 

Times estimated + , . 
Times estimated— . . 
Times estimated = . . 



12 3 4 5 



20|40 60 801100 
|241919! 23 

1 1 l{ 
4 4 1 



7 8 9 10 11 12 13 14 15 



100100100100100 



131 18 
91 1 

2 5 



18 18! 12 
4 17 
2 5 5 



lOOlOOlOOlOOilOO 
19 19 17 151 12 

2 2 3 3 5 

3 3i 4 6 7 



ascribed to faulty attention, though, possibly, the fact that the 
weights are of equal size may have clouded the direct perception 
of weight by lifting. 

(3) In general, the suggestion is still working, though less power- 
fully, at the 15th trial: in other words, it has persisted, for most 
>S's, through the successive lifting of 10 equal weights. 

(4) There is a marked drop in the judgment 'heavier' at the 6th 
weight, i.e., at the first 'trick' weight — a drop which is, obviously, 
due to a 'disappointed suggestion,' analogous to that which con- 
ditions the size-weight illusion of the preceding test. In the pres- 
ent instance, S is, in most cases at least, prepared to find the 6th 
weight heavier than the 5th : he puts forth more effort ; the weight 
rises with unexpected ease, and is, therefore, often judged 'lighter.' 
If, however, S is more influenced by his expectation of 'heavier' 
than by the unexpected lightness of the weight, he still judges 
'heavier,' or he may, from the conflict of these two tendencies, 
judge 'equal.' 

(5) Practise has very httle effect upon the suggestibility of 
*S's: at least Binet found that, when 12 older children (16 years) re- 
peated the test by the first method five times in immediate succes- 
sion, there was no alteration in the average number of times that 
suggestion appeared (the average number of suggestions in the 
five trials was 5.1, 4.9, 5.4, 5.0 and 5.5, respectively). 

(6) Tentative experiments indicate that age apparently has less 
effect upon suggestion by progressive weights than upon sugges- 
tion by progressive lines (see the following test) : in trials by the 
first method, 12 children aged 16 years responded, on the average, 
with 5.1 suggestions, whereas 24 children aged 8-10 years, re- 
sponded, on the average, with 6.75 suggestions. 



414 SUGGESTIBILITY 

(7) According to Binet, comparison of the results of this test 
with other tests of suggestibility, especially the line-test, indicates 
a fair degree of correlation, so that, while the sense-department 
under examination may in part determine the extent of sugges- 
tion, very suggestible S's may be expected to prove noticeably 
suggestible in all tests. On the other hand, tests undertaken at 
the Educational Laboratory at Cornell University^ do not con- 
firm Binet's statement, and lead one to believe that Scott's con- 
clusions (Test 44) are correct, when he asserts that there is no 
such thing as general suggestibility. 

(8) Procedure by the second method (compulsory lifting of the 
antecedent weight) makes the real progression (1st five weights) 
more uniformly evident, but reduces the illusory progression. 

(9) Procedure by the third method (estimates of each weight) 
produces less suggestion than the first, but more than the second, 
method. Inspection of the estimated weights (grams) shows (a) 
that S's have a decided preference for the use of numbers terminat- 
ing in or 5, (6) that no one of 24 *S's overestimated the 5th weight 
(100 g.), but that they commonly greatly underestimated it (30 
to 50 g.), and (c) that those S's that showed the greater number of 
suggestions also gave, on the average, the largest quantitative 
estimations for the illusory increments : the correlation of sugges- 
tibility for these two methods of treatment was found by Okabe 
and Whipple to be 0.53. 

REFERENCE 

A Binet, La suggestibilite, Paris, 1900. Ch. iv. (pp. 261-208). 

TEST 42 

Suggestion by progressive lines. — The purpose and general plan 
of this test are the same as in the preceding test of suggestion by 
progressive weights, and the details are again derived from the 
work of Binet. 

' These tests, which were conducted by T. Okabe, under the author's 
directions, included all the suggestibility tests of Binet, together with the 
warmth tests (No. 44) . The results of their application to 29 S's indicate 
almost total lack of correlation of suggestibility in the several tests. A full 
account will appear in the Journal of Educational Psychology. 



TEST 42: PROGRESSIVE LINES 415 

Apparatus. — A sheet of cross-section paper, ruled in millimeter 
squares. Kymograph drum, with kymograph or some form of 
supporting stand. Cardboard. Strip of white paper, 15 X 50 cm. 
Drawing utensils. 

Preliminaries. — Arrange the kymograph drum so that it may 
lie horizontally and be revolved freely by hand. It may conve- 
niently be left in the kymograph with the driving 'step' loosened, 
or be placed in the smoking stand. On the strip of white paper, 
draw with a ruling pen 20 parallel, straight, black lines, 2 cm. apart 
and each 1 mm. wide. The lines must begin at varying distances 
from the left-hand margin: the first four are to be 12, 24, 36, and 
48 nun. long, respectively; the remaining IG are to be each 60 mm. 
long. Support the sheet of cardboard vertically in front of, and 
close to the kymograph drum, and cut a horizontal slit 1 X 12 cm. 
through the cardboard in such a position as to expose the ruled 
lines, one by one, as they are turned past the slit.^ 

Method. — Seat S 50 cm. from the screen and provide him with 
a sheet of cross-section paper. The instructions should take the 
following form. "I want to try a test to see how good your 'eye' 
is. I'll show you a line, say an inch or two long, and I want you 
to reproduce it right afterwards from memory. Some persons 
make bad mistakes; they may make a line 2 inches long when I 
show them one 3 inches long; others make one 4 or 5 inches long. 
Let's see how well you can do. I shall show the line to you through 
this slit. Take just one look at it, then make a mark on this paper 
[cross-section paper] just the distance from this edge [left-hand 
margin] that the line is long. When that is done, I shall show you 
the second line, then the third, and so on. Make the marks for the 
second on the Hue below the first, the third on the next line, and 
so on. "2 

' In default of the kymograph, the strip of ruled lines may be laid flat upon 
the table and exposed through a 1 X 12 cm. slit cut in the center of a sheet 
of cardboard 55 cm. square. 

Or, the test-lines may be drawn as sections of radii upon a cardboard disc 
which is supported vertically just behind the screen and rotated to bring 
them into view successively. 

- These directions should be followed with some care. In tests of sugges- 
tion, the slightest change in the setting of the test, or in the manner or con- 
tent of the instructions, may materially affect S's attitude toward the experi- 
ment. The object is to convey the idea of a straightforward test of accuracy 
of line-reproduction, and to avoid arousing any suspicion of snares or tricks- 



416 SUGGESTIBILITY 

E then turns the drum to bring the first, or shortest, line into 
view. As soon as *S turns his attention to the recording of his esti- 
mate on the paper, the drum is moved forward sHghtly to conceal 
the line so that further comparison is impossible. As soon as S 
has placed his mark, then, and not before, the next line is exposed. 
This precaution serves to maintain the impression that a new, and 
hence probably a longer, line is exposed. Slow S's may need to be 
hurried; too quick ones may need to be checked, so that the inter- 
val between successive exposures shall be approximately 7 sec. To 
keep S's attention alive, E may accompany the exposures with 
non-suggestive remarks, e.g., "Here is the second line." "Here 
is the third," etc. 

If *S has ceased to respond to the suggestion of progressive aug- 
mentation at the 20th exposure, the test ends at that point : if 
not, E should, without *S's knowledge, bring the drum back to the 
5th line, and continue the exposures of the series of 60 mm. lines 
as before, until S does cease to respond to the suggestion. 

E should note and record any significant features in S's manner, 
e.g., signs of embarrassment, hesitancy, automatic response, etc. 

When the test is completed, and provided no further tests of 
suggestibility are to be undertaken at the time, E will find it ad- 
vantageous to quiz S with regard to his attitude toward the test. 
This interrogation must be verj' tactfully conducted. E may, 
for example, begin by asking: "Are you entirely satisfied with 
what you have done"? If S answers in the affirmative, let E 
continue with such inquiries as: "Do you think you have made 
any mistakes"? "Did you make any lines too short or too long"? 
"At what moment did you notice that your lines were too long"? 
"Why didn't you make them shorter"? etc. If S confesses that 
he made some mistakes, let him take his record-sheet and make the 
changes that he thinks ought to be made to produce a correct 
record, using small circles for his corrections to avoid confusion 
with his first estimates. 

Variations of Method. — E may, if desired, adopt the arrange- 
ment first used by Binet, according to which there are 12 succes- 
sive stimulus-lines, all of which begin at the same distance from 
the left-hand margin, and which have the following lengths: 12,24, 
36, 48, 60, 60, 72, fS, 84, 84, 96, 96 mm. It is evident that numbers 



TEST 42: PROGRESSIVE LINES 417 

6, 8, 10, and 12 constitute four 'trap-lines,' since the arrangement 
suggests progressive augmentation, whereas each of these four lines 
is equal to that which immediately precedes it. 

Treatment of Data. — (l) For a measure of suggestibility, E 
njay take the number of lines out of the last 10 lines that are 
drawn longer than the 5th line was drawn. 

(2) A coefficient of suggestibility may also be calculated, fol- 
lowing Binet's method, by the formula 

X : 100 = max. L : 5th L, 
in which 

a; = the required coefficient, 
max. L = the length of the maj^imal line recorded by S, 
5th L = the length of the 5th line as recorded by S. 
Absence of suggestibility is, then, indicated by a coefficient of 
100 : presence of suggestibility by a coefficient of over 100. 

(3) When the variant method is used, the degree of suggesti- 
bility may be determined roughly in terms of the number of 
'traps' in which S is 'caught,' or more exactly, by the formula 

X : 100 = c: r, 
in which 

X = the required coefficient, 

c = the average recorded increment of the four trap-lines, 
r = the average recorded increment of the four lines imme- 
diately preceding the four trap-lines. 

Results. — (1) In his examination of pupils in the elementary 
schools, aged 8-10 years, Binet found that the coefficient of sugges- 
hM% ranged from 109 to 625. In 16 of 42 pupils, the coefficient 
was 200 or over, i e., the maximal line was double or more than 
double the 5th line.^ 

With the variant form of test, Binet found the coefficient lying between 
7.6 and 120. No one of 45 children avoided all four 'traps,' and 36 children 
avoided none of them. Occasionally, the trap-line, presumably on account 
of the contrast between the stimulus and the child's expectation, was actu- 
ally recorded as shorter than the preceding line. S's whose coefficient in 
this form of test is 100, i.e., whose average increment for the trap lines is 
the same as for the objectively progressive lines, are termed 'automatic' 



^ For detailed records of a number of individual cases, consult Binet, 124 ff . 



418 • SUGGESTIBILITY 

(2) The point at which fnaximal suggestibility is registered is 
commonly between the 19th and the 25th line, but may lie any- 
where between the 7th and the 36th (this being the limit tested 
by Binet). 

(3) Inspection of the records of individual pupils shows that 
in some cases the force of suggestion was steady and persistent, 
while in others it reached a maximum, and then declined. 

(4) Extremely suggestible S's may make their 'estimate' of the 
line without even looking at it when exposed; their minds are 
so completely dominated by the suggestion of uniform augmenta- 
tion that they do not trouble to observe the stimulus. 

(5) The degree of suggestion induced by this test declines 
markedly with age: Binet found, for instance, that the coeffi- 
cients of suggestibility, in the case of 12 pupils whose age averaged 
16 years, ranged only from 103 to 146, and the author has not been 
able to produce appreciable suggestion in scattered tests of college 
students. 

(6) In either form of test, the 1st line is apt to be overestimated. 
The 5th line is almost invariably underestimated. Generally 
speaking, this underestimation is less pronounced in those *S's that 
prove least suggestible. 

(7) In many instances, the records bear witness to a struggle 
between the directive idea of progressive increments and the 
impressions which are actually received from the lines as they are 
exposed. Especially characteristic is the appearance of a number 
of estimates in which the directive idea is effective, followed by a 
sudden reduction in estimation, which is again followed by another 
series of progressive increments. In other words, the idea of pro- 
gression is operative until a point is reached when the recorded 
length is manifestly too long. S makes, then, a more or less marked 
correction, but does not, curiously, relinquish the notion of pro- 
gression, and this again becomes manifest. 

(8) The corrections made by young *S's during the inquiry that 
follows the test cannot, of course, be taken as exact indications of 
the extent of the suggestion or of their consciousness of error. It 
will be found that many S's are conscious that they have made the 
lines too long; some can also explain why they made them too long, 
but it is rare that any one gives a satisfactory explanation of why 



TEST 43: SUGGESTION BY PERSONAL INFLUENCE 419 

he continued to make them too long, after he realized that he had 
been overestimating. 

(9) Correlations. Tests of school children and of adults by 
Okabe and Whipple afforded the following correlations (footrule 
method) : Suggestibility for progressive lines (number of * yields') 
and suggestibility for progressive lines (maximal divided by the 
5th line) 0.38. Correlation, by either treatment, with contradic- 
tory suggestion (Test 43) about 0.25, with directive suggestion 
(Test 43) about 0.20, with suggestion for warmth 0.17, with the 
size-weight illusion (Test 40) . 10 by the first, and —0.14 by the 
second method of computing suggestion for progressive lines. 

REFERENCE 
A. Binet, La suggestibilite, Paris, 1900, pp. 83-160. 

TEST 43 

Suggestion of line-lengths by personal influence. — In the 

three preceding tests suggestion is produced by the objective 
conditions of the test: in everyday life, however, suggestion is 
often produced by personal influence, by authoritative statement 
or command, or merely by what Binet terms 'moral influence.' 
Two forms of line-test have been utilized by Binet to study 
this variety of personal suggestion: the first he terms 'contra- 
dictory suggestion,' the second 'directive suggestion' (sugges- 
tion directrice) : in the former E makes certain statements that are 
intended to interrupt or modify a judgment that S has just made; 
in the latter, statements that are intended to control or influence 
a judgment that S is just about to make. 

A. CONTRADICTORY SUGGESTION 

Materials. — Drawing utensils. A sheet of cardboard upon 
which are drawn in ink 24 parallel, straight, black lines, ranging 
in length from 12 to 104 mm., by increments of 4 mm. The lines 
all begin at the same distance from the left-hand margin, are 7 



420 SUGGESTIBILITY 

mm. apart, and are numbered in order of their length, from 1 to 
24. Three rectangular pieces of cardboard, about 12 X 20 cm., 
on each of which is drawn a single straight line. These three 
stimulus-lines correspond to numbers 6, 12, and 18 of the 24 
comparison-lines, and are, accordingly, 32, 56, and 80 mm. long, 
respectively. 

Method. — Show S the card of comparison-lines, and explain 
their numbering. Replace this by the first stimulus-line (32 mm.), 
saying: "Look carefully at this line." After 4 sec, remove the 
stimulus-card, present the comparison-card, and say: "Tell me 
the number of the line that is just the length of the one I showed 
you." At the moment that S gives his judgment, E says: 
"Are you sure? Isn't it the — th"? — indicating always the next 
longer line. If S answers "No," E repeats the question in exactly 
the same form. If S still answers "No," the attempt to produce 
suggestion is suspended, and the case is recorded as one 'resis- 
tance.' The second and the third stimulus-lines are presented 
and the same procedure is followed in each case. If, in any of the 
trials, S answers "Yes," E then inquires : "Isn't it this one"? — 
indicating the next longer line, and this inquiry is carried on from 
line to line until S has twice resisted the suggestion, i.e., has twice 
answered "No" to the same question.^ 

Treatment of Data. — Following Binet, *S's suggestibility may 
be rated in terms of the total number of 'advances' in lines that 
he makes, under inquiry, in all three trials. Thus, if he 'yields' 
two lines the first time, three the second, and none the third, his 
suggestibility is rated as 5. 

Results. — (1) Children tend to select for their first line one 
that is shorter than the stimulus-line. ^ 

(2) Of 25 children, aged 8-10 years, Binet found 6 who resisted 
suggestion completely, 6 who 'yielded' once, 5 twice, 2 three 
times, 2 four times, and one each six, seven, and more than seven 
times. 

^ Once more it should be said that it is highly important to follow the 
same form of inquiry, to use the same tone, the same attitude, in every ques- 
tion for every S, since the suggestion which we seek to measure is condi- 
tioned by the character of the inquiries. 

^ E is almost always, therefore, in a position to demonstrate to S, if need 
be, after the test, that his suggestion would have been a sound one to follow. 



TEST 43: SUGGESTION BY PERSONAL INFLUENCE 421 

(3) Preliminary experiments conducted by Binet and Henri 
upon 240 pupils, with some slight changes in method (particularly, 
giving an opportunity both for direct comparison and for selec- 
tion by memory after a 12 sec. interval), yielded the results (2: 
p. 343) indicated in Table 86. 

TABLE 86 
Percentage of ' Yields' to Contradictory Suggestion {Binet and Henri) 

AVERAGE AGE MEMORY TEST COMPARISON TEST MEAN 



7-9 


89 


74 


81.5 


9-11 


80 


73 


76.5 


11-13 

1 


54 


48 


51.0 



Here it is evident that E's suggestion is less effective when S 
can make direct comparison of the lines, and that suggestibility, 
under either direct comparison or comparison from memory, 
declines with age. 

(4) S's who have selected the correct line are less apt to change 
their designation under suggestion than are S's who have selected 
the wrong line: thus Binet and Henri found that 56 per cent 
changed their selection when it was actually right, but 88 per. 
cent when it was wrong. Moreover, of the latter, 81 per cent 
made the change in the proper direction. 

B. DIRECTIVE SUGGESTION 

Apparatus. — As in Test 42, save that only the 60 mm. lines are 
used. 

Method. — Seat *S 50 cm. from the cardboard screen and provide 
him with a sheet of cross-section paper. Instruct him as follows: 
"I'm going to show you a number of lines. You will see them 
appear through this slit, one at a time. When I show you a line, 
take a good look at it; then make a mark on this paper at just the 
distance from this edge [left-hand] that the line is long. When 
that is done, I shall show you the second, then the third, and so on. 
You will make the mark for the length of the second line on the 
second line of your paper, for the third on the next line, and so on." 



422 SUGGESTIBILITY 

E now displays the 5th, i.e., the first 60 mm. line of the series, 
with the remark: "Here is the first one." When S is ready for 
the second line, i.e., 7-10 sec. later, E remarks, as he exposes it: 
"Here is a longer one." When the third is exposed, he remarks 
"Here is a shorter one;" and he continues to use these remarks, 
alternately, at the moment of exposure of each line, until 15 lines 
have been exposed, the first without suggestion, the remainder 
coupled with 14 suggestions — 7 of shorter, 7 of longer. These sug- 
gestions must be given just before the line is exposed, in a quiet 
tone, without looking at ^S. *S should see the disc turn and the new 
line appear at the moment that he receives the suggestion. 

If tlesired, iS may be questioned afterward, as indicated in Test 
42, with regard to his altitude toward the suggestions. 

Treatment of Data. — When »S accepts the suggestion, record 
a 'plus' case; when he resists the suggestion, either by making the 
length equal to that of the preceding line, or by altering the length 
in a direction contrary to the intent of the suggestion, record a 
'minus' case. The algebraic sum of these plus and minus cases 
may serve as an index of /S's suggestibility. Record should also be 
kept of the extent of modification (in mm.) made by S in each trial. 

Results. — (1) The verbal directive suggestion used in this test 
is more potent, at least for children 8-10 years old, than the auto- 
suggestion intluced in Test 42. Sixteen of 23 pupils tested by Binet 
submitted completely to the suggestion,' and no one resisted every 
suggestion. 

(2) The suggestion is, in general, stronger at the outset than 
toward the end of the series, as is indicated by the fact that the 
extent of modification of line-length decreases, and the number of 
complete resistances increases, as the series progresses. 

(3) Verbal suggestion is commonly more effective in producing 
augmentation than in producing reduction in line-length, in the 
proportion of about 5 to 4. 

(4) There are marked individual differences in the suggestibility 
of school children under the conditions of this test. Binet found 
that in 18 trials the number of resistances to suggestion ranged from 
to 14. (See Binet, 1, pp. 228-9, for a detailed table.) 

' This statement is made in the text, but does not appear to be l)oriie out 
by Binet's table (1, pp. 228-9). 



TEST 44: ILLUSORY WARMTH 423 

(5) The first line is practically invariably underestimated. 

(6) Tests upon 10 children, whose average age was 17 years, 
showed less suggestibility than in the case of younger children; 
still, four of the 17 accepted every suggestion, and three others 
resisted suggestion only once. The average extent of modifica- 
tion produced by suggestion is, however, less than that in the case 
of younger >S's. Again, the extent of modification is practically 
constant throughout in the series with the older S's, but large at 
first and then progressively less in the series with the younger ;S's. 

REP^ERENCES 

(1) A. Binet, La suggestibilite, Paris, 1900, especially 219-243. 

(2) A. Binet and V. Henri, De la suggestibility naturelle, in Revue philos., 
38: 1894, 337-347. 

TEST 44 

Suggestion by illusion of warmth. — In measuring either dis- 
criminative or liminal sensitivity, difficulty is not infrequently 
caused by the interference of auto-suggestion (see various tests of 
Chapter VI). In the immediately preceding tests (Nos. 40 to 43), 
a process of discrimination (of weights and line-lengths) was, 
accordingly, made the basis for testing suggestibility. In the pres- 
ent test, a (supposed) measurement of liminal sensitivity is made 
the basis for testing suggestibility. The plan is to arrange experi- 
mental conditions in such a way as to suggest warmth, when no 
warmth is present. 

This idea seems to have originated in the Yale laboratory, when 
Seashore (4), in 1895, worked out a proposal made two years 
earlier by Scripture (3). Small's varied tests of suggestibility 
(5), which appeared in the following year, embodied two very 
simple 'heat' tests. More recently, Guidi, in 1908, and Scott, 
in 1910, have reported tests of suggestibility to warmth, the 
former with a simple 'warmth box,' the latter with apparatus 
somewhat similar to the original device of Seashore . Four methods 
are described herewith; the resistance-wire method of Seashore 
and Scott, the heated box method of Guidi, and two simple 
methods employed by Small. 



424 SUG 3ESTIBILITY 

A. ILLUSORY WARMTH — RESISTANCE-WIRE METHOD 

Apparatus. — Stop-watch. Special warmth-tester. 

The warmth-tester consists of a wooden l)ox, open at the end facing E, 
and provided, on the top, with porcehxin sockets for four electric lamps, 
wired in multiple, and with a snap switch by which the current (105-110 
volt, D. C.) may be turned on or off. The wiring is purposely left visible, 
and leads conspicuously from the lamps to a coil of No. 24 German-silver 
wire, 1 m. long, which is wound, without covering, about a flat piece of hard 
rubber, 3 X 10 cm. This resistance coil is fastened to the front of the box, 
in such a manner that it may be easily reached by *S, without exposing his 
fingers to the warmth of the lamps on the top of the box. A concealed cir- 
cuit leads to a noiseless switch, underneath the box, which can be operated by 
E without aS's knowledge. By means of this switch, E may shunt the current 
through the coil, or cut the coil out entirely, without affecting the illumina- 
tion of the lamps. 1 

Preliminaries.— Find an arrangement of lamps such that, when 
the current passes through the coil, warmth becomes perceptible in 
8 to 10 sec. Four 8-C. P. carbon-filament lamps generally prove 
satisfactory. If necessary, use one or more 16 C. P. lamps. A 
more powerful illumination, with the same heating effect in the coil, 
may be secured by the use of tantalum or of tungsten lamps. 

Method. — Give S the following instructions: "I want to test 
your ability to perceive warmth. Hold this coil of wire gently 
between your thumb and two fingers, like this [illustrating]. You 
will see that the coil is connected with these electric lamps, so that, 
when I light them, a current of electricity can flow through the 
coil and warm it — it is made of German-silver wire, and offers a 
slight resistance to the current. There is nothing at all to be 
afraid of. You can't feel any shock from the current, nothing but 
a slight warmth. Watch carefuUj^ and, the moment that you feel 
warmth, say 'now.' " 

Without attracting aS's attention, close the secret coil-switch, 
so that no current passes through the coil. After a preliminary 
^ ready,' snap the lamp-switch rather ostentatiously; start the stop- 
watch at the same instant, and lean forward in an attitude of 
expectancy, keeping one hand on the lamp-switch, as if awaiting 

' In default of a 110-volt circuit, a resistance-wire apparatus may be 
contrived with a battery, after the plan described by Seashore, though the 
absence of the illuminated lamps alters the experimental conditions. 



TEST 44: ILLUSORY WARMTH 425 

vS's 'now.' Snap the lamps off as soon as the 'now' is spoken. 
Record the time. Feel of the coil, or solicitously blow upon it, 
as if to cool it. Repeat the test 5 times with each hand, alternately. 

If S, at any trial, fails to get the illusion of warmth within 60 
sec, open the coil switch (without S's knowledge), so that warmth 
is actually felt, but record the trial as one 'resistance,' or failure. 

Variations of Method. — -Following the plan of Seashore and 
of Scott, tell S that 20 trials will be made. Give a preliminary 
series of 5 trials with each hand, with objective warmth from the 
start, in each trial. Without interruption, continue with an equal 
number of trials in which the coil is not warmed unless S fails to 
report warmth within a period some 10 sec. longer than the aver- 
age time at which he had reported warmth in the first 10 trials. 

Treatment of Data. — In either method, suggestibility is 
measured by the absolute or relative number of trials (without 
objective warmth) in which S reports warmth. 

S may also be rated in terms of the quickness (number of sec- 
onds) with which the illusion is reported. 

B. illusory warmth — GUIDl's METHOD 

Apparatus. — Stop-watch. Matches. Alcohol lamp, fitted 
with hinged extinguishing cap. Cubical wooden box, with a chim- 
ney-like metal top, a circular hole in the front face, and a hinged 
door in the back face (Fig. 57). 

Method. — £"s instructions are analogous to those in the resis- 
tance-wire method. "I want to test your ability to perceive 
warmth. I want you to thrust your forefinger into this box through 
the hole in front. I shall put this lamp into the box. It won't 
burn you at all. Just watch very carefully, and say 'now' the 
moment that you notice any warmth in the box." E then light, 
the alcohol lamp, opens the door of the box, sets in the lamps 
extinguishing the flame as he does so, starts the watch, closes the 
door, and expectantly awaits S's judgment.^ 

' Guidi's method deviated somewhat from the above, in that S was in- 
structed to push his finger slowly into the box, and degree of suggestibility 
was measured by the extent to which the finger had been inserted when 
warmth was reported. This pi'ocedure presents difficulty in governing 
the rate of movement, and has, so far as the author's experience goes, no 
advantages over the procedure that has been recommended. 



426 SUGGESTIBILITY 

C. ILLUSORY WARMTH — SMALL's METHOD 

Materials.- — Alcohol lamp. A pin thrust through the rubber 
tip of a pencil, or through a small bit of soft wood. Toothpick, or 
other bit of wood with a blunted point. Matches. Piece of card- 
board, about 15 X 15 cm. Blindfold. 

Method. — (1) Let S see the lighted lamp and the pin in its 
holder. Instruct him as follows: "I am going to warm this pin 
in this flame, then touch it to the back of your hand to see if you 
can notice the warmth it makes. Don't be afraid of being burned, 






Fig. 57. guidi's apparatus for the warmth illusion. 
(Modified by Whipple.) 

as it will not be hot enough for that, and I shall try it on my own 
hand first. Say 'now' when you feel its warmth." Blindfold S 
carefully. Go through the operation of heating the pin; say 
'ready,' but do not touch S's hand at all. If S reports warmth, ask 
him to describe the feeling: if he does not report warmth, repeat 
the test, but touch him on the back of the hand with the pointed 
piece of wood, to see if the contact is reported as 'warm' or 'hot.' 



TFST 44: ILLUSORY WARMTH 



427 



(2) Light a match and move it around about 1 cm. above the 
back of S's hand. Call his attention to the 'waves of heat' that 
he feels. Blindfold him carefully. Ask him to see if he can detect 
the heat waves every time. Strike a match, and move it about 
over his hand, but hold the cardboard between the match and the 
hand. Repeat several times with either hand. Note the number 
of times the suggestion is 'accepted,' and any indications of the 
readiness or degree of suggestibility. 

Results for all Methods. — (l) In general, the results of the 
warmth-illusion test appear to be conditioned primarily by the 
success of the investigator in creating a proper atmosphere of. 
suggestibility, rather than upon the particular apparatus employed. 
Thus, Seashore met with amazing success. Of his 8 college stu- 
dents, only 3 resisted at all, and these but once or twice each, so 
that, in 420 trials, there were only 5 failures to perceive heat. 
Small tested boys and girls from the 7th grade and the high school : 
in 21 trials, 5 reported heat, with no contact at all, 19 reported heat 
from the wooden point, while in 19 trials with the "heat-waves," 
17 proved suggestible. 

Of Scott's 20 college students, 9 'yielded' 10 times (of a possible 
10); 5 yielded 9 times; 2 yielded 4 times, and 1 each, 8, 7, 5, and 
3 times. No one of the 20 aS's resisted in every trial. 

Okabe, who worked with school children and adults in the Cor- 
nell laboratory under the author's direction, obtained positive 
results in 70.7 per cent of the trials, and with 22 of 29 S's (Table 
87). The Italian children tested by Guidi were less suggestible 
(at least for his method), as Table 88 shows. 



table 87 
Suggestibility to Warmth. Resistance-Coil Method {Okabe and Whipple) 



Men 

Women 

Bright boy 
Dull boys. 

Totals 



73 



29 



157 



HI 



70.7 



428 



SUGGESTIBILITY 



(2) The relation to sex and to age can not be stated with assur- 
ance. Guidi's results indicate maximal suggestibility at the age of 
9, but the Cornell tests, perhaps from being too few in number, 
failed to show characteristic differences between grammar-school 
boys and adults. It is likewise unsafe to generalize from the 
indications there given of the greater suggestibility of men. 

TABLE 88 
Suggestibility to Warmth, as Related to Age. 187 Cases (Guidi) 



ge 


6 


7 


8 


9 


10 


11 


V2 


13 


14 


er cent 




















SJUggCS- 

tible . . . 


50 


40.9 


51.8 


62.5 


50 


40 


33.3 


21.4 


27.3 



15 



33.3 



(3) The degree of suggestibility, as indicated by the readiness 
with which warmth is felt, differs, as might be expected, in dif- 
ferent »S's, i.e., even of those who invariably perceive warmth, some 
report only "faint warmth," others "sudden heat," etc, Guidi 
classed his pupils into three groups, according as they took the 
suggestion quickly (in 1 to 2 sec), moderately (2 to 3 sec), or 
slowly (after 3 sec), and found 33 per cent, 63.7 per cent, and 3.3 
per cent of his >S's in these three classes, respectively. 

(4) Scott found no correlation between suggestibility as meas- 
ured by the warmth illusion and suggestibility as measured bj^ his 
flight-of-colors test. Okabe's tests afforded the following low 
correlations with other forms of suggestibility tests; with pro- 
gressive lines (Test 42) 0.17, with contradictory suggestion (Test 
43) 0.21, with directive suggestion (Test 43) 0.29, with the weight 
illusions (Tests 40 and 41) none. 



REFERENCES 

(1) G. Guidi, Recherches exp6rimentales sur la suggestibility, in Ar. P., 
8: 190S, 49-54. 

(2) W. D. Scott, Personal differences in suggestibility, in P. R., 17: 
1910, 147-154. 

(3) E.W. Scripture, Tests on school children, in Educ. Rev., 5: 1893, 52-61. 

(4) C. E. Seashore, Measurements of illusions and hallucinations in 
normal life, in Yale S., 3: 1895, 1-67, especially 30-32. 

(5) M. H. Small, The suggestibility of children, in Pd. S., 4: 1896, 176- 
220, especially 183-186. 



CHAPTER XT 
Tests of Imagination and Invention 

Imagination, like most of the stock psychological terms, has the 
misfortune to be used in several different ways. In popular usage, 
imagination commonly implies something fanciful and unreal: 
we condemn a rumor, for example, by dubbing it "a mere figment 
of the imagination." In psychology, imagination has both a gen- 
eral and a specific meaning. Broadly speaking, imagination is 
equivalent to imaging, or thinking in images, as over against 
perceiving — re-presentation as contrasted with presentation. But 
the psychologist also differentiates between imaging which refers 
to some part of one's past experience (memory) and imaging, 
which, though necessarily based upon this same material, presents 
the material in new forms or patterns, and which is not felt to 
refer definitely to some part of one's past experience. This latter 
is imagination in the specific, or narrower meaning of the term. 

A further distinction is made between imagination which occurs 
under passive attention, as illustrated in reverie, musing, or 
dreaming, and imagination which occurs under active attention, 
and which is marked by persistent, purposeful effort to dissociate 
former combinations of experience and to reorganize them into 
some new plan. We have, then, a distinction between passive 
imagination and active, creative, or productive imagination. 

The five tests of this chapter are designed both to secure indi- 
cations of the wealth of spontaneous imagery in phantasy, and to 
measure capacity for creative or inventive thinking. 

In so tar as inteUigence denotes not merely good attention and 
good memory, but also inventive capacity, ability to plan and 
organize, to anticipate, or to "put two and tAvo together" CEbbing- 
haus' kombinierende Tdtigkeii), in so far must the attempt to meas- 
ure intelligence employ tests of productive imagination and inven- 
tion. It goes without saying that the tests here described do not 



430 IMAGINATION AND INVENTION 

exhaust the possibilities ot investigation in this important field of 
mental activity. Undoubtedly, new tests will be devised which 
will prove of value in supplementing those heretofore employed. 
We need especiallj^ a series of tests of inventive capacity, of graded 
difficulty, which shall put less emphasis upon linguistic attain- 
ments. 

TEST 45 

Ink-blots. — In their discussion of a proposed series of tests 
for the examination of individual differences in mental traits, 
Binet and Henri, in 1895, suggested that fertility of visual imagina- 
tion might be investigated by means of a series of ink-blots. Two 
years later, G. Dearborn published brief suggestions for making a 
series of blots, and in the following year described the results of 
the use of 120 blots in the case of 16 Harvard students and pro- 
fessors. Since then Kirkpatrick has tried the ink-blot test with 
public school children of 8 elementary grades, and Miss Sharp has 
followed the suggestion of Binet and Henri in a study ot individual 
psychology upon graduate students in Cornell University. 

The ink-blot test is commonly classed as a test of passive imagi- 
nation, under the assumption that S simply looks at the blot and 
allows his associative processes to suggest to him whatever 'pic- 
tures' they may. In practise, however, S is quite likely to search 
actively for these associations, so that the mental activity con- 
cerned is, perhaps, more allied to active than to passive imagina- 
tion. 

Materials. — Standard series of ink-blots, numbered from 1 to 
20. Stop-watch. Paper properly prepared for recording *S's 
statements. 

The primary difficulty heretofore existing in the application of the ink- 
blot test has been the lack of standardized material. To meet this difficulty, 
the author has prepared the series of blots just mentioned by using zinc- 
block prints, so that investigators may now apply the same series of blots, 
and thus secure strictly comparable data. Unfortunately, this series has 
not yet been applied upon a sufficiently extensive scale to render it possible 
to publish norms of performance for the test. 

Method. — (a) Full procedure. Instruct ^' as follows: "I have 
here a series of 20 odd-shaped ink-blots. 1 want you to take them 



TEST 45; INK-BLOTS 431 

ill order from 1 to 20, one at a time, to look them over at your 
leisure, and to tell me (or write down on a numbered blank) what 
things you can see in each blot. Try them in different positions. 
Ot course, these blots are not really intended to be pictures of 
anything, but I want to see whether your imagination will suggest 
pictures of things in them, just as you sometimes try to see 
what objects you can make out of clouds." Let S take his own 
time. Especially with younger »S's, it is better for E to record the 
results, so that S may be perfectly free to enumerate as many 
things as are suggested to him. 

Kirkpatrick used only four blots, and allowed each pupil one minute to 
name as many associations as possible for each blot. Miss Sharp used 10 
l)lots, and allowed only 5 minutes for the test. 

The test may be conducted with a group of tS's by distributing the cards, 
and having them passed successively from member to member of the group 
until each S has written his associations for each card, but this method has 
obvious disadvantages. 

(h) Shorter procedure. Following the method used by Dearborn, 
arrange the 20 cards face down in a pile, with the 20th card at the 
bottom, the 1st at the top, and the numbered edges toward S. 
Instruct S as follows: "Each of these 20 cards has on it an odd- 
shaped ink-blot. When I say 'now,' turn over the first card in 
this way [illustrating the movement that will expose the face of 
card No. 1 with the numbered edge toward *S]. Look at the 
ink-blot, without turning the card in anj' other position, and say 
' now' (or tap on the table) as soon as you have thought of some- 
thing that the blot resembles. Of course, the blot is not really 
intended to be a picture of anything, but I want to see whether 
your imagination will suggest some 'picture' in it, just as you 
sometimes trj^ to see what object you can make out of a cloud." 
Give the command ' now' ; start the stop-watch at the same time. 
When S gives his signal, stop the watch, record the time and the 
object or association given by S. Continue in the same manner 
with the remaining cards. 

Treatment of Data. — In the full procedure, the score is based 
upon the average or total number ot associations: in the shorter 
procedure, upon the average speed of the single associations. It is 
also possible to form some estimate, in either case, of the type, 



432 IMAGINATION AND INVENTION 

richness and variety of »S"s imagery by classifying the associa- 
tions after some such plan as that ilhistratecl l^elow from Miss 
Sharp's results. 

Typical Results. — The following associations for the 20 cards 
of the standard series are taken from the records of three adults, 
and will serve to indicate the variety that may be expected when, 
the records of several /S's are compared. 

(1) A lady seated on a couch. A witch riding on a new moon 
across the sky. A moose's head. A woman, sitting on a bank of 
shrubs, waving a handkerchief. 

(2) Child, crouching in fear. Alan with grotesque features. 
Ugly old colored woman. 

(3.) A banner. Aright-angled triangle. TheGodBilHken. An 
Egyptian idol. A jade-stone idol. 

(4) A large beetle. A boat load of excursionists. A lobster. 
A spider. Potatoes. A dirigible balloon of the Zeppelin type, 
with a cloud of steam or smoke overhead, and a grappling-anchor 
trailing below. 

(5) A pig. A woman with a big head of hair. A butterfl}'. A hole 
through the ice. A girl wearing a tam-o-shanter cap. Human 
liver and heart. A rock. 

(6) Woman running and holding her skirt. Woman with a muff 
in her left hand, and her hat almost blown off. A broken bellows. 
Merry Widow waltz. 

(7) Large caterpillar on a horse's shoulders. A devil bending 
over something. An old man. A dream monster. 

(8) Human torso. Hot and cold water faucet in a bath tub. 
Person with head bent forward, holding sticks in her hand. Heads 
of two birds trying to sAvallow what is between them. 

(9) A goat with a pack on his back. A turkey with drooping 
wings trailing on the ground. 

(10) Ugly man's head. Head and arm of a woman with a lighted 
candle in her hand. A dachshund running off with some one's cape. 

(11) Map of Scotland and Ireland. Owl that has just placed a 
fish before him on the branch of a tree. Some specimen in geology. 
A tree bloAvn in a heavy gale. 

(12) Alap of United States and part of Canada. A chicken lying 
on its back. An Indian head. A woman sitting on a cliff under a 
tree, reading a novel. 

(13) A flying squirrel. The skin of a bear. A hen sitting on a nest. 

(14) A crab. A bat with outspread wings. A moth. A neuro- 
logical shde. 

(15) Section of medulla oblongata. Two nuns bowing their 
heads together. A tulip. A false mask. 



TEST 45: INK-BLOTS 433 

(16) Closed hand with thumb and Uttle finger, or a sixth finger, 
projecting. A loving cup. A tea-pot. 

(17) A root. A porcupine. 

(18) A Chinese dragon, as seen on packages of fire-crackers. 
Branch of a gnarled oak. 

(19) Bird alighting on a nest. A flying squirrel. 

(20) Man pulling off his sweater. Runner leaning forward to 
start a foot-race. Photographer, with focussing cloth over his 
head. Crocodile suspended bj'- the head. Bear with the grand- 
mother's night-cap and gown, as illustrated in Little Red Riding 
Hood. 

General Results. — (1) Speed of association. In 1920 trials, 
Dearborn found the average time for making a single association 
to a blot to be 10.3 sec. This seemingly long time may be due to 
the difficult nature of some of the blots in his series. 

(2) Dependence on age. Kirkpatrick states that "younger 
children seemed more suggestible or imaginative, as they named 
more spots." This conclusion is based upon the data presented 
in Table 89. 

TABLE 89 

Average Number of 'Names' given to Ink-Blots (Kirkpatrick) 



GRADE 


I 


II 


III 


IV 


^- 


VI 


1 

TII 1 


vni 




... 2.9 


2.5 


2.6 


1.8 


1.9 


1.7 


2.1 


2 2 







It is evident that something besides a simple decline of 'imagination' 
with age is exhibited in this table. In explanation, Kirkpatrick says : ' ' The 
younger children seemed to have no doubt whatever of the spot being a 
picture of the object they named, while the older children simply said 'it 
is some like' or 'it looks a little like, 'adog,' 'cloud,' or whatever else was sug- 
gested. This superiority of the small children is striking when we consider 
that the number of mental images that they have is much smaller than that 
possessed by older children, who may name a part of the body or the map of 
a country or something else that the younger children know nothing about. 

"The smaller number of objects seen in the spots by the children of the 
4th, 5th, and 6th grades is probably to be explained by the fact that children 
of those ages have become more critical in their sense-perception, as their 
ideas have become more definite, and as they have learned from life's ex- 
periences and from training to be more careful in their judgments. The 
older pupils of the 7th and 8th grades, on the other hand, have passed into 
another stage in which they realize that a picture is not necessarily this or 
that, but may resemble any one of several things, hence they are not afraid 
to say what it looks like." 



434 IMAOINA'l'ION AND INVJON'I'ION 

(3) Dependence on occupation. J)(':iil)()ni Ix^liiiVCK that, at hsast 
inrnat\irer/S's,thcrc8ultH of the ink-hlot test arc; (;oii(htion(!(J, nol so 
much by ago or sex directly, as l)y ha])its of living, occupation, 
and other environmental factors: thus, we should expect charac- 
teristically diffcjrent r(!sults from the; test when a|)pli(Hi, for (example, 
to artists, farmers, lal)or(!rs, prof(!ssioiial men, to the city-hred or 
tlu^ country-bnMl, etc. 

(4) Individual differences, both in speed, numl)(!r and type of 
asscxiiation setnn to have been clearly marked and fairly constant, 
whenever the tcist has been applied. Thus, in Dearborn's single- 
association method, the highest agnicmeiit in the answers of his 
*S;'s for any one card was but 40 per cent, whih; for sc^vcral cards, 
no two S'h gave the same answer. 

As regards fertility of imagination, Miss Sharp noted that the 
most imaginative S in her group saw 81 objects, the least imagi- 
native but 27 objects in the same 10 blots. TIk; same investigator 
believes, however, that all *S's might be roughly divichid into two 
groui)S, (a) the (!onstructiv(; or imaginative;, who put tog(!ther coii- 
crclc details "in such a way as to form a significant whole," and 
{!)) tlic iiiatt(!r-of-fa(!t, or scientific; type, given more to analysis 
than to creative synthesis.' 

Ah (!xiuii|)I(!H oI" Huh (lilTerciKie, Llio following reports Irom I. wo of MIhs 
SIuxi'p'h »S"h may 1)0 iiuoUid: both refer to tho ono blot,. 

(1) Ass<)('i<Uionti fetv and n(>n-r<iiifil.rvclivc. "An ouk'';. SliilTcid turkey. 
Ib'iul iiikI neck of a musk-rat." 

(2) AtisocidiianH numerous <m(l ronxirur.iivc. "Ciini-He. I'ndiislorie bin! 
in fliglil,. ji'airy riding on a bunible-boe. Bit of Ijopical j untile, with trailing 
gray nioHweH and |)()ols of water. Japanese lady. Hit of landscape with two 
liillsanda valley betwiien— an army (Micaniped under one hill. Moss-grown 
log floating in wM,tcr. Fabulous monster (grillin perhaps), walking off on 
liis hind legs with a small llotteid.ot under his arm." 

(5) (^ualilaiive ciasKiJlcation. It is oft(;ii possil)l(! to classify 
the associations peculiar to a given .S'. Thus, Miss Sharj) mentions 
MS classificatory groups: (a) conunon-place, every-day obje(!ts, 
such as domestic utensils, tools, ])lants, and particularly animals, 
(h) scientific o])j(;cts, su(;h as geometric figures, schematic drawings, 

' It is tempting to regard this classification as id(!nti(;al with the common 
classitK^ation of laboratory »S"s into 'snbjcMd.ive' and 'objective' ()bs(!rvers. 



TiOKi' K): mnoiiistk; invkniion llif) 

(c) ()l)j(;(',ts Hiit!;};csl,('<l by lil.criiry (•(•iniiiis(;(;ii(!(;, iuid (d.) oliji'cl-s 
IVoiri i";iJ)lc ;ui(l iriyllioloKy, siic.li UH ccuilaurH, dni^jjoiiK, witclicH, 
liiirics, etc. SoriH! >S"s cxhibii/ variety of uHHociaiioii, in ilial/ Uicy 
(•il(! ()l)j('(tl,s 1 li;il Ixrloiif^ to M(;v(!ml of Quw. i£,r(>u])H; ol-lKiCK jin; tniicli 
less f'('r1,il(! in iniafiiiialion and coui'itw. UicMm-lvcH largely to ;i 
Hiti}^,l(' tyfx' (»r irii;ifi;cry. 

iM';kI';i{,I';n(;ms 

(\) A. I'.iricl iiiul V. Ilciiri, f-u pHycholo^if! iiidi viducllf, in A. I'., 2: IHOr. 
riWdj, 411 40.-,, (.H|,(;(;i!illy 444. 

f2) ('.. Dciul.orti, I'.lols of ink in cxiHTiiiicnl;!! \>ny<:\><,\<nry, ii' !'■ K-, 1: 
iS07, ;{!K) I. 

C.i) ('.. Dc'ul.oiti, A HliKly of i(ii!iKifi!i,l,ioris, in A. .1. I',, '.r. ISOS, IH!', MM), 

(^) K. I<irl<|.;.(.if;k, In<iivi.lii'il loHtH of h<;IiooI chiMi-n, in I'. I{,, 7: lOOO, 
271 2M). 

^'")j ,Sif;ll;i 10. Hliarp, Irulividnal jwyclioloKy: a Hlndy in pHydiolri^'ifiil 
ni.Uiod, in A. .). I'.,»]0: A(»ril, 1809, .T20 ;«M. 

TEST 46 

Linguistic invention, 'i'tic ink-hloi ioHt HCirvcH fjrirnarily a- 
ii Icsl of visu.'d linaK'^ry. lint an (;von rnon; frijiU'ul rtoutcc of 
individual (WiU'rcnccH in crcativf; ability njay b(! found in linguistic 
invention. Mis.s Sharp, actinj; Ufjon the KU^X'-HtionH of IVinct and 
Henri, t(;,st('d what kIu! iunuH 'literary ifriaf/jination/ in threr; wayn, 
vi/; by tiie dcvelof)fn(;nt of K(!nt(;riC(;H, by tin; dev(;lofj/nent of a 
f.'iven 1 heme, and fjy ifie choice, of a topic ffjr cojr)f)OHition. The 
last-narne(J t(!Ht HeerrjH, for tfie fjniKerit i)uri>o,s<;H, to have relatively 
Hlif^lii value: on the other iiand, the conHtruction of H(jntenceH may 
be testefl eit}i(!r, an waH (Jonc; by MiHH Sfiarp, i)y asHij^ninj^ three 
vvorrJK whir;h muHt be ine(jrf)orat(;d into a Hfiritencr;, or, an wan done 
later by I'inet, by >z;ivinj^ S f)artially written K(!nt(!ne<!H to be com- 
pleted. 

liefort; undertakinj^ t}ie;se three; ffjrmai tcHtH, however, it iKdenir- 
ai;le, if tiie purpose in mind into make a qualitative ntudy of the 
mental type of individuaLS"H,to inHtitute a f)reliminary inquiry e,(jn- 
cerninj^ the general literary tasteH anrl habilH of each H. The <;xaet 
nature of this infjuiry rrnjst, naturally, be Jidiifiled (o ( lu; aji;e and 



436 IMAGINATION AND INVENTION 

training of the S's: the following are some of the points that have 
b3en covered by investigators: (1) list of favorite books, (2) 
statement of favorite type of reading, (3) statement of the maga- 
zines, periodicals, newspapers, etc., ordinarily read, (4) list of books 
(outside of classroom or professional work) read during the last 
year, (5) statement of favorite games and evidence of enjoyment 
of games, like chess and checkers, that demand creative activity 
and foresight, (6) fondness for the theater, drama, music, painting 
and other forms of art, etc. 

A. DEVELOPMENT OF SENTENCES 

Method. — Ask S to write as many sentences as possible con- 
taining the three nouns: citizen, horse, decree. Each sentence must 
contain all three nouns, though it may contain others as well. The 
sentences are to be as varied as possible. Five minutes are allowed. 
Continue the test with four more sets of nouns, and afterward make 
similar tests with five sets of verbs. For the noun tests, use as 
additional sets: (2) bell, ground, owner, (3) skill, modification, 
-picture, (4) cup, fraction, money, (5) letter, laiv, summer. For 
verbs use (1) bless, destroy, ivrite, (2) make, correspond, remain, 
(3) require, choose, run, (4) see, find, throw, (5) remember, put, 
depart. In the noun tests, 'S is permitted to use either singular or 
plural forms, and possessive as well as nominative or objective 
cases: in the verb tests, he may use any form of the given verb, 
e.(j., blessed, to bless, will bless, etc., as well as bless. 

The tests ma}^ be conducted with individuals or with groups, 
but il may be preferable, especiallj^ with young S's, to work individ- 
ually and to let *S dictate the sentences instead of Avriting them. 

Treatment of Data. — The quantitative score is determined 
by averaging the number of sentences written by S. The qualitj^ of 
wo k may be graded upon any convenient scale, e.g., 1 to 5,^ corrc- 
sj omhng to five degrees of excellence. Miss Sharp used the sym- 
bols .4, B, and C, and indicated intermediate grades ]\v the use 
of — and -f . For purposes of computation, she then assigned 
numerical values to these symbols, as follows: A— = -iO, A = 
50, .4 + = 60, B- = 80, 5 = 100, B-\- = 120, C- = 160, C = 
= 200, C -F = 240. In practise, tliis scoring is virtually equiva- 



TEST 46: LINGUISTIC INVENTION 437 

lent to estimating quality of work in terms of average number ot 
words per sentence, and this simpler metiiod may be used for the 
qualitative score. 

Typical Results. — (1) The following are selected single sen- 
tences reported by Miss Sharp for the first test : 

1. "Decrees are made for citizens, not for horses." (The connection of 
the words here is simple and mechanical.) 

2. "That stalwart citizen on the great gray horse is a man to he trusted 
uith the decree." (This implies a concrete situation.) 

3. "All the well-to-do citizens of the village, each niounlcd on a horse, 
rode through the streets, proclaiming their dissatisfaction with the new 
decree." (A situation is here more fully outlined.) 

(2) The following is a full set of sentences written by a grad- 
uate student, in* 5 min., for the first assignment: 

1. A decree was posted that the citizen should not abuse the liorse. 

2. The horse of the citizen was sold by official decree. 

3. "Here," said the citizen, "is the horse mentioned in the decree." 

4. Early in Arabian history, a decree raised to a higher caste, a citizen 
who owned a horse, but later, possession was sufficient for l)etter standing, 
and the law was not needed. 

5. If a citizen keep a horse, it is a decree that he use it kindly. 

6. "What a funny decree," exclaimed the citizen, when he read of the 
horse sun-bonnet law. 

7. The decree was signed that the horse had kicked the citizen, and there- 
fore the injured man could collect damages from the owner of the animal. 

8. "Time is up," cried the citizen, stop-watch in hand, " I hereby decree 
that you write the word horse and stop at once." [Faulty on account of 
the use of 'decree' as a verb.] 

(3) The following represent groups of sentences written for the 
author by two college students (selected at random from a num- 
ber of papers) for the fourth set of verbs. The relatively greater 
variety of the second group is clear. 

A. 1. "I saw the book and tried to find a place in which to throw it." 

2. "I threw the cat in the creek and turned to see if anyone had found 
me out." 

3. "I see that I can find nothing to throw at him." 

4. "You see, it was this way, I simply found the hatchet and threw it." 

B. 1. "The child saw a horse, found a stone and threw it at him." 

2. "When you find a clover, see if it has four leaves: if not, throw it 
away." 



438 



IMAGINATION AND INVENTION 



3. ' ' Throw the paper out of the window and see if it will find a good land- 
ing place." 

4. "Find me a pencil, then I will see if I can find out the solution to the 
problem which is on the paper that you threw into the basket." 

5. "The boy found an apple, but when he saw it was decayed, he threw 
it away." 

Conclusions.^ — (1) Dependence on 'part of speech assigned. 
All aS's tend to write fewer, but better sentences with verbs than 
with nouns. 

TABLE 90 

Scores of Seven Adults in Developing Sentences (Sharp) 





QUANTITY OF WORK 


QUALITY OF WORK 




Average 


Maximum Minimum 


Average Maximum Minimum 


Nouns 'given' 
Verbs 'given' 


4.6 
3.8 


6.6 3.2 
5.8 2.5 


79 113 1 55 
93 133 54 



(2) The rank of aS's, both in quality and quantity of work, is the 
same when nouns and when verbs are assigned. 

(3) " In general, the subjects who made the most sentences made 
the most elaborate, and those who made the fewest sentences made 
also the simplest and most unimaginative." 

(4) This test correlates with the ink-blot test, in so far as those 
*S's who show most constructive capacity with the blots also show 
most constructive capacity in the development of sentences. 

B. COMPLETION OF SENTENCES 



Materials. — Printed forms containing 25 beginnings of senten- 
ces,2 with spaces for the completion of each sentence. Piece of 
white cardboard. Stop-watch. 

Method. — Give S the following instructions: "On this paper 
there are printed the beginnings of a number of sentences. I am 
going to show these to you, one at a time. As soon as I show you 

^ These are all drawn from the work of Miss Sharp. 

- The first 20 sentences are taken, with such slight modifications as trans- 
lation has suggested, from Binet. The last five (since Binet prints but 20 
of the 25 he recommends) have been supplied by the author. 



TEST 46: LINGUISTIC INVP^NTION 439 

one, I want you to write the rest of the sentence. You can write 
anything you want, as long as the whole sentence will make sense 
when you have finished it." If >S fails to understand what is wanted, 
supply him with an extra paper in which a few trial sentences have 
been written in pen and ink, and show him how they might be 
completed. For the test proper, cover the entire test-blank with 
the cardboard: after a warning 'ready,' expose the first incomplete 
sentence. '^ Start the watch at the same time. Record as nearly 
as possible the time used by S in starting to complete the sentence, 
■i.e., the time he takes, after he reads the sentence, to 'get an i(k'a.' 
The timing should be done without >S"s knowledge. 

Treatment of Data. — Compute the average, or determine 
the distribution of the times needed by S to start the 25 sentences. 
For a qualitative index, estimate as well as possible (preferably 
by using some such system of scoring as that described in the de- 
velopment-of-sentences test) the general value of the completed 
sentences. S's sentences may also, if desired, be classified in re- 
gard to type, e.g., vague or meaningless, commonplace, reminis- 
cential, imaginative, aphoristic, etc. 

Results. — (1) Binet found characteristic differences in the speed 
of work of his two daughters, Armande and Marguerite. Thus 
Armande's records show 12 sentences started in less than 5 sec, 
4 sentences in from 5 to 10 sec, 6 in from 10 to 20 sec, one in 28 
sec, and one in 70 sec Marguerite's records, on the other hand, 
show but one sentence started in less than 5 sec, but 7 sentences 
in less than 10 sec, and the remainder in much longer times, e.g., 
20, 50, and 70 sec. 

(2) Binet's two >S"s also showed characteristic differences in 
the type of sentence-completion: Armande is poetic and imaginative; 
Marguerite's sentences are more precise, more practical, more in 
accord with real life, less emotional. For example, for Sentence 
1, Armande writes: "I entered the field by a covered footpath." 
Marguerite writes: "I entered a grocery and bought two cents 
worth of chocolate." 



iThe sentences have purposely been numbered from the bottom of the 
page so that the cardboard will not interfere with S's writing. 



440 IMA(;i NATION AND I N V I'.N KION 



DKVKI.Ol'MKNT OK A i'llKMI 



Mk'I'iioi). Sii|)|)I> N with \vritiii«; malcrinls, mihI ^ivc him 10 
mill. ((If pcrhnps loiigci' ii" workinj; with youuj;" »S"s) to write upon 
soiiicthcmcs(>l('d(Ml I'roiu the following: (1) The Death of a I hnj, (2) 
The iUtplure of a Fortress, {\i) The Kscape of a Prisoner, (4) A 
Forest Fire, (5) The Mission, of Music, (0) The Influence of Neirs- 
papers, (7) The Delays of J asti.ee, (8) A Trip inn Flyimj Machine} 

'PuKATMKNT OK Data. — (^iiiuility or speed of work in;iy hr 
iTckoiied with ;ipproxiiniiie iiccuincy 1)\ coiiiit iii.tj; thenuinhei' oi' 
words written in tlu> iis.si}>;iie(l time: (pi;iiity of work, which is 
e(pi!illy import ;in(, cspec'uilly in the t reat men!, of imaginative 
(hemes, must l»e esliMiakul by F after a, trial has shown what ina.v 
Ite deemed |)oor, and whut good work for >S"s of t he a^e under inves- 
lifi;atioii. tonality niiiy he recorded in (he manner ah'eady iki- 
scribed, or upon (he basis of 100, as in grading scliool con»i)ositions. 

liiosiii/rs. (1) 'V\\v relative; ininiber of ideas ehU)ora(ed by 
dil"f(>ren(^ *S"s is indicated with fair api)rt)xiinalion by tlie relative 
number of woi'ds written, so that nunibei' of words may stand 
as ;i f.iir index of lluency of ick'ation and gencM'al iingnistit; readiness. 

(2) As a rule, more words an> written upon imaginative, than 
upon expository themes. Sharp's l)est *S wrol-e in 10 min., on an 
averag(>, 25!) words upon iiuagimitive, and 222 upon (expository 
(hemes; her poorest N wrol(\ on (he average, 121 and !)l words, 
respect i\-ely, for the same types of (JuMues. 

(;{) Those ,S"s that show conslructive ai)ili(y in (he ink-blo( test, 
and in the de\-elopnient^ of sent (>nc(\s, also exhibi( the same sup(>- 
riori(y here in I he de\(>iopinen(. of (hemes. 

No'ri'.s. These (ests of linguistic iinention migh(, without 
greal. ditliculty, be p:tr:dlel(Ml in other lields of conslructive el'foit. 
\ test of musical aliilit\- (of t h(« crejitive sort) might, for example, 

' 'I'lic lirst of liu'sc (licmcs \v;i.s iis(mI l)y IMnot in iu.s coinpar.'il i vc study 
of (lie iiumiIm.1 i)roc('.ssi<s of his two (lauglitcrs: Mio aoxt six wore iisoti for 
a siiniliu- jiin'oose in Miss Slijirp's study of imivcM'sity students — the lirst 
tincc of (lu'in hcinnttcsi^ned to involv»> iiuiiginativo, the sccoiul three oxposi- 
itory tiH'aliuent: the last tiieiue is siiHM;»'sted l)y the author .as more suitable 
for younger iS"s, To secure a more n^liahle estimate of N's elliciency il is 
d(>siral)l(^ th.at mor(> tluin om^ theme should he developed. 

'I'his lest lends itself re.adilv to ^roup InvitnuMit, since it involves;! f:unil- 
i.-ir tv|>e of sehool aetivitv. 



'I'jos'r 17: woud-huii.ding Ml 

l)c devised by .'iskiiifi; N's lo linisli ;i, p.-irTudly j^iveii iiiiisie;il llieine, 
or lo const iilcl ;i siinple melody IVorii ;i, ^iveii series of notes. 
Siiiiil.'ii'ly, ceilnJii for-ms of ;u-tisli(', iiivenlioii iniji;lil, l)e ieslcd by 
askiiifi; >S"s lo skel.cli designs for vvnll-p.'iper or pnl.lcfiis for V<'ne- 
liiin iron-work. 

Miss SliJU'i)'s U'A, of i\u) choice of u Mieine vvus coiiduclc*! I»> 
Mskinf^ >S"s to s(!l(!cl-, from t,li(t followiufi; K) tJicitu'S, tJiosc; five upon 
wliieli tliey would prrjfcr to write, if iisk(ul to do ho: A. lrniiji;in;itivc 
llienies, (1) in (I ^lummUmn, (2) A Polar Jjdnd.scapc, CA) A Pvri- 
liin SahhiUh, (4) My Opposite Ndi/hbor, (5j Man iJudaircd in'lli 
iJie Poior/r of FLighl: li. JOxpo.sitory tlicmcH, (()) (/Ivilizitllon not 
licgc/rumiUon, (7) Wisdom in (Uiarily, (S) Frierahhip of Hooks, 
i\)) Fidion (IS a, V chide of Tndh, (10) The PJlofpwnrc of Ihc Hot 
011(1 iJiol of iJic I'lilpil. The expository tluiines were }i;ener;illy 
preferred, hut some N's, who, MS oIIhu'S tents showed, hiid lil.tje 
e;i,p;icily 1(» Imndle im;ifi,iii;i,l ive lliemes, did select sevecjil Irom I his 
division. 

HI'IFKIil'JNCICS 

(1) A. liinotJiiul V. Ilciu'i, Lii psyclioloKie ii)(|ivi.|iicllc, in A. I'., 2: 
IS!)5 {mm), 411-405, oHrxJcially 444. 

(2) A. liiiiot, LYiLudc! v.x\){'.r\uw.\\UvU'. de ritil.i^llinctncr, i'aris, l!)()2. 
i'p. ;{()!). I'lHiJCcialiy cli. \. 

{:*■) Sicllii V). Sluu'f), Iiiilivi'liiiii j).sy(!li()l()^;y: ii nl,ii(ly in psyc'liolonii-n! 
iiicIIkhI, in A. .J. I'., H): IS!M), :',29-.'3!) 1 . 

TEST 47 

Word-building. The word-buildinp; test wus Hiipj^cstcd \>y 
th(! fumiliur };:u)ie of ioiii,fi;rains 5is well as hy tin; advcrtisemenis 
often s('(;u in niufijazini^s in whicli a, prize; is ofTere(| lo the person 
who Can make the; most words I'rotn a fijivcn word or series of lei icrs. 
'i'his t(!st is easily administcrcid and (!valuat(!<l: it is one Hint enJI- 
for infj;cmiity and !u;tive jdtention: it mifi;fit fairly he said to demnnd 
that ability to combine isohited ft;i,{!;m(Mits into a whole, which 
lObbinjijhaus has declared 1,o be; the e.ssencc; of intciilifiicmH' and for 
Hie m(!asur(!m(!nt of wliich \\o. devised his well known 'cnmi)l(!tion 
method;" and finally, its (!X(!Cutioii is conditioned to a, certain 
extent by the ricluuissand n^adini^ss of the examinee's w ). d-voca,bu- 

' Sec TcHt No. 4S. 



442 IMAGINATION AND INVENTION 

lary. One may expect, therefore, to find a correlation between 
this test and the vocabulary test (No. 50) and possibly between 
it and school standing or general intelligence, and other tests of 
creative literary ability. 

Materials. — Two specially prepared blanks, the first of which 
calls for combination of words from the letters a, e, o, b, m, t, the 
second from the letters e, a, i, r, I, p. 

Method. — Provide S with the first test blank, and give him 
the following instructions: "Make as many words as you can from 
the six letters given on this blank. You may use any number of 
letters from one to six, but no letter may be used twice in the same 
word, and no other letters than these six are to be used. You will 
have five minutes." Conclude the test by use of the second blank 
under the same conditions. 

Results. — The author has elsewhere (2( reported the results of 
the use of the first test-slip with two groups of college students 
and a group of 50 boys from the 7th and 8th grades of the Ithaca 
public schools, and of the second test-slip with the same college 
students. From this report the following statements are drawn: 

(1) As will be seen in Table 91, the second slip offers more 
possible combinations, so that more words and a greater number of 
different words are made with it. 

table 91 
General Results in Word Building {Whipple) 



Test 


Grade 


Male 


Female 


Largest 


Smallest 


Average 


Mean 
Varia- 
tion 


Total 

No. 

Different 

Words 


Possible 
Words 


1 


College 


7 


15 


25 


10 


18.6 


3.54 


41 


70 


1 


" 


9 


27 


26 


10 


18.6 


3.30 


41 


70 


1 


Grammar 


50 





21 


6 


12.4 


2.37 


38 


70 


2 


College 


7 


26 


32 


14 


21.9 


4.00 


57 


105 


2 


i< 


9 


27 


33 


15 


23.5 


3.66 


61 


105 



(2) The individual differences in rank are large: thus it happens 
that not a few grammar-school boys make more words than some 
of the college students: to be more explicit, it may be stated that, 
with the first test, 10 grammar-school pupils make 15 words or 
over, while 13 college students make fewer than 15 words. 



TEST 47: WORD-BUILDING 443 

(3) By examining the papers in detail, and tabulating the total 
number of words formed and the number of times each of these 
words is given, one may discern something of the principles which 
govern the operation of the test. The following are the data thus 
secured: 

Test No. 1. 58 College Students. (45 Different Words.) 

Over 50 times — bat, mat, bet. 

40-49 times — eat, met, Tom, at, boat. 

30-39 times — meat, to, tea, beat, team, tab, ate, am, moat, mob, 

me, beam, toe. 
20-29 times — tame, boat, be, mate. 
10-19 times — boa, mote, bate, abet, tomb, tome, tam. 
5- 9 times — Mab, Abe, Mae, ma, atom, a. 
1- 4 times — hot, mot, o, Moab, be^a, bema, ta"->e. 
Not given^ — ab, ambe, ambo, amt, atmo, ba, bam, bo, bom, boma, 
bote, ea, eam, eb, em, eta, mao, meta, mo, nioa, moe, ob, obe, 
om, ta, tambo, tema. 

Test No. 1. 50 Gramiviar-Grade Boys. (38 Different Words.) 

Over 40 times — mat, bat. 

30-39 times — bet, at, met. 

20-29 times — ^to, eat, Tom, beat, tea, meat, be, am, boat. 

10-19 times — toe, mob, beam, me, ate, team, tab, boa, oat. 

5- 9 times — ma, bate, a, moat, mot, tame, mate, bot. 

1- 4 times — tam, tomb, Abe, mote, Moab, Mae, o. 
Not given — those not given by college students, plus abet, atom, 
bema, beta, Mab, tabe, tome. 

Test No. 2. 69 College Students. (66 Different Words.) 
Over 60 times — lip, lap. 

50-59 times — rip, rap, pear, ear, real, pie, leap, rail, pale, reap. 
40-49 times — reap, pail, pile, ale, pair, are, ape, lie, pea, peal. 
30-39 times — pare, earl, pearl, air, par, lair, ripe, liar. 
20-29 times — ail, Lear, rape, ire, pal. 
10-19 times — lea, pa, rile, pire, era, pier. 
5- 9 times — per, a, alp, Eli, plea. 
1- 4 times — I, paler, peril, lira, rep, rale, ile, lare, ra, pil, piler, 

ril, April, Ira, la, pareil, pi, pilar, Rea, Rae. 
Not given^ — ai, aiel, aile, aire, al, apl, ar, Ariel, aril, ea, el, ela, 

epi, er, eria, il, irp, le, lep, lepra, lerp, li, lier, lire, lirp, paie, 

pali, parel, pari, pela, pel, pia, piel, pila, plie, plier, prial, prie, 

re, rei, rial, ril, ripa. 

'This list is based on the words actually given in the Standard Diction- 
ary, not including, however, Scotch terms. 



444 IMAGINATION AND INVENTION 

Inspection of these lists shows (a) that three-letter words are 
in every instance those most frequently formed, (6) that two- 
letter words and the one-letter words, which one might expect 
to be most frequent since most simple, stand relatively low, 
e.g., ma, he, am, pa, me, a, o, I,^ (c) that grammar-school boys give 
all the words given by college students save a few rather unusual 
terms such as atom and tome, {d) that usage and ordinary speaking 
vocabulary condition the formation of words, in as much as the 
most ordinary words have the greatest frequency, e.g., hat, mat, 
het, eat, lip, lap, whereas words that are less frequently used in 
every-day speech, although their meaning is doubtless perfectly 
well known, do not suggest themselves so readily under the condi- 
tions of the test, e.g., tomb, tome, era, plea, paler, (e) that the words 
not given by any one are, with one or two exceptions, e.g., plier, 
words of extremely rare usage or unusual form, alternative spellings, 
etc. 

Terman has pointed out still other iactors that condition the 
outcome of the test. " Much depends, of course, upon the vocabu- 
lary at command, and this in turn depends largely upon home 
training and amount of habitual reading as well as upon native 
retentiveness. A second factor is abilitj^ to spell, and habits of 
word analysis generally. Veiy important, also, is the use of a 
rational plan; some skipped about and made combinations at 
random, while others took the letters one by one and joined them 
in as many different ways as possible with the others. Lastly, the 
rate of shifting of attention, and the degree of mental inertia as 
opposed to spontaneity, also contribute to the result" (1, p. 342). 

(4) Sex differences may not with certainty be made out, yet, 
as Table 92 indicates, in every group tested, the men did slightly 
better than the women: though this difference is small — less than 
the mean variation, yet it is constant in direction in all four in- 
stances. 

(5) In the case of grammar-school pupils no correlation could 
be established between word-building and class standing: in the 

' It appeared, upon inquiry, that some of the college students had omitted 
words like pa, ma, a, o, and / on the ground that they were 'not real words,' 
or 'didn't count,' but, oftener, they seem to have been passed over because 
the attention was concentrated upon the making of comhinations. 



TEST 48: EBBINGHAUS' COMPLETION METHOD 



445 



case of the 58 college students there appeared the insignificant 
correkticn, r = + 0. 13, P. E., 0.08. Terman, however, found 
his stupid boys generally inferior to his bright boys. 

TABLE 92 

Sex Differences in Word-Building (Whipple) 



TEST 


DATE 


MEN 


AVERAGE 


WOMEN 


AVERAGE 


1 


1906 


7 


18.7 


15 


18.6 


1 


! 1907 


9 


19.7 


27 


18.0 


2 


1 1906 


7 


23.6 


26 


21.4 


2 


1907 


9 


25.8 


27 


22.7 



REFERENCES 

(1) L. M. Terman, Genius and stupidity: a study of some of the intel- 
lectual processes of seven 'bright' and seven 'stupid' boys, in Pd. S., 13: 
1906, 307-373. 

(2) G. M. Whipple, Vocabulary and word-building tests, in P. R., 15: 
1908, 94-105. 

TEST 48 



Ebbinghaus' completion method.— In July, 1905, the school 
authorities of Breslau requested certain persons, among them Pro- 
fessor H. Ebbinghaus, to undertake a scientific investigation of the 
fatigue-effects of the continuous five-hour session then in vogue 
in that city. In the course of this investigation, Ebbinghaus 
devised and apphed, in conjunction with other tests, what he 
termed the 'Cotnhinationsmethode' (since referred to by Elsenhans 
(2) as the 'completion-method' and by others as the mutilated 
text test).' 

' Meyer (6) has pointed out the inaccuracy of the translation "combina- 
tion-method," which has been current for some time. The German Com- 
binationsgabe is not a talent for combination, but an ability to "put two and 
two together," or, to use Meyer's explanation, "a talent for drawing con- 
clusions from premises which do not very readily pi'esent themselves to a 
man's consciousness as items of a unitary logical thought, but which, as soon 
us they are combined, suggest the conclusion very forcibly." This is quite 
true, but the author can not see that Meyer has improved matters by advo- 
cating the translation "conjectural method." To conjecture is to surmise, 
to guess, to form a tentative opinion, inferentially. Technically, the activ- 
ity in the Ebbinghaus test might be labelled 'redintegration,' but, as this 
term is somewhat clumsy, the designation 'completion method' seems 
entirely adequate. 



446 IMAGINATION AND IMVENTiON 

The author of the method says in substance: Mental abihty 
demands not merely retentive capacity, readiness of recall, or 
facile asjiociation of specific past experiences; it demands all this 
and something more, something more complex and, as it were, 
creative ; namely, the ability to combine, into a coherent and signifi- 
cant whole, mutually independent and even seemingly contra- 
dictory impressions. In short, intelligence is essentially a combina- 
tive activity. To measure intelligence, therefore, we must employ 
a test that demands ability to combine fragments or isolated sections 
into a meaningful whole. Such a test may be afforded by muti- 
lated prose, i.e., by eliding letters, syllables, words, or even phrases, 
from a prose passage and requiring the examinee to restore the 
passage, if not to its exact original form, at least to a satisfactory 
equivalent of it. 

On account of the enthusiastic statements of Ebbinghaus, who 
characterizes this method as "a real test of intelligence," and as 
"a simple, easily applied device for testing those intellectual 
activities that are fundamentally important and significant 
both in the school and in life," the test has assumed some promi- 
nence. Thus, Wiersma used it to determine the relative force of 
sex, age, native talent, and school training as determinants of the 
mental efficiency of his pupils; Terman used it in his study of 
stupidity and genius; Krueger and Spearman embodied it in their 
investigation of the correlations between different phases of 
mental capacity, while Lipmann and Wertheimer expanded it into 
a diagnosis-of-fact test {Tathestandsdiagnostik). Its usefulness 
as a measure of fatigue, which has been questioned especially by 
Kraepelin, has, however, been more or less lost sight of since its 
initial employment for that purpose by Ebbinghaus. 

The completion method is peculiarly difficult to class psycho- 
logically, for the simple reason that the nature of the mental pro- 
cesses that it demands depends almost entirely upon the numlx^r 
and kind of elisions that are made in the text. To take extreme 
cases, if the elisions are numerous and sweeping, it may become 
really a linguistic puzzle of a very difficult variety, and it then 
l)elongs rather in the group of tests of active or creative imagination 
of the literary type : if, on the other hand, the elisions are but few 
and simple, it may degenerate into a simple test of controlled 



TEST 48: EBBINGHAUS' COMPLETION METHOD 447 

association of any desired degree of ease. Again, if the mutilated 
text be first read to the examinee, as some, e.g., Elsenhans, suggest, 
the test becomes in the main a test of associative recall, i.e., a 
form of memory test. 

Again, since the elision of a single letter may, in some circum- 
stances, very considerably increase the difficulty of the test, it fol- 
lows that, without extensive preliminary trials, it is well-nigh 
impossible to prepare a series of texts of equivalent difficulty, or 
to insure that the several sections within a givtMi text present 
equivalent difficulty. 

The following is :i sample section of text as used by P]bbinghaus and other 
German inv stigators: the dotted lines indicate the position and approxi- 
mate lengfli of the omissions. 

Belagerung Kol bergs. 1807. 

"Da der Feinrl fortf an .... neuen Schanze am Sandwege. . . . 

angestr Eifer zu so hatte unser neuer Kommandant 

gleich ersten Nacht Hicrseins einen Aus dieselbc 

angeordnet," etc. 

Terman elided, in the main, whole words, instead of syllables, on the 
ground that the word is a more natural unit of language than the syUablc, 
and that ability to supply missing syllables will, in the case of school chil- 
dren, depend largely on the extent to which word-analysis has been taught 
in the schools: this varies in different school systems and even in different 
classes of the same system. lie employed one text with, and one without 
preliminary reading. Since these are the only English texts that have been 
employed, they are prescribed for the test. There has also been added 
another text (No. 1), arranged by the author in accordance with Ebbing- 
haus' plan of eliding portions of words as well as entire words. 

Materials. — Stop-watch. Three printed texts. [If all three 
texts are to be used for the test, E should prepare a short sample 
piece of mutilated text, say three or four lines, which may be type- 
written, or placed on the blackboard for group work, and used for 
demonstration and preliminary trial. If one of the texts is not 
used, this may serve the purpose.] 

In the reproductions here given, italics indicate the elisions in the printed 
texts. Text No. 1 contains 100, Text No. 2, 93, and Text No. 3, 100 elisions. 



448 IMAGINATION AND INVENTION 

Text No. 1. 
Where the Dandelions Went. 

Wh^^M Willy lodfi two years old, he lived in a red farm-hoM.se iviih a yard 
in front of it. The dandelions were very thick there; so that the yard looked 
yellow instead of green. 

One bright day Willy's mamma i)ut on Ian stravy hat and sent him oul into 
the yard to play. She knew the yard had a high fence; and he could not 
open the gate; so he was safe. When it was time for him to have a nap and 
she wont lo call him, she noticed that a great many of the dandelions were 
gone. She wondered where they were; but, as Willy could not talk much, 
she did not ask him about them. 

A short time after, while he was asleep in his crib, his mamma went oul 
to draw some water. When the bucket came up full of water, the top was all 
yellow with dandelions. Looking down into the well, she could see no water 
at all, only dandelions. 

It was no wonder, then, where the blossowis had go7ie. Willy h<id been 
very busy, trying to fill up the well. 

Text No. 2. 
The Strength of the Eagle. 

One day the eagle went with the other birds to see which could ^?/ </ie high- 
est. They agreed that he who could fly </ie highest should he called the strongest 
bird. All started at the same time and j^ett) away among the clouds. One by 
one they grew weary and returned, but the eagle j^ew upward and upward 
until Ae was a mere speck in the heavens. . When he came back, the others 
were waiting for him; and when he touched the ground a Yvnn&i fleio off his 
back where he had been hidden and said that he himself was the strongest 
bird. "I am stronger than the eagle," said the linnet, "for not only did I 
fly as high, but wheii he began his downward flight, I left my hiding place 
and //eiy up a little higher." At this boastful speech the oi/iers ,s/lOo^• their 
heads and eaWed a council to decide the matter. After a long debate they 
decided that the eo^^e was the strongest bird, /or not only did he fly so high, 
but he carried the linnet as well. 

To <Ms day the plumes of the eagle are emblems of atrenglh and ronnigc. 

Text No. 3. 
Why the Mole is Blind. 

All I ndlaii once chased a squirrel into cloud^onrf. Then he set a trap for him, 
laugliing to think how he would catch him. The squirrel did tiot conic back, 
but alas! the sn7i on his daily rounds fell right into iAe <my>. 

When the bright sunlight did not come, the Indian began lo Uv uneasy, 
and when he found his Iraji had Ihc .•<iin fast he did not know what lo do. 

lie tried lo get near enough lo loosen the cords, l)ut Ihe heal from tlie sun 
scorched him and he gave // uji. 



TEST 48: EBBINGHAUS' COMPLETION METHOD 449 

Then he coaxed many animals to try it, but they all found the sun too hot. 
At last the mole said: "I will dig through the ground under the trap and so 
get at the cords." 

This he did and the sun leaped up into the heavens. 

But it went so quickly that the poor mole could not gei away, and the Aeai 
of the sun put out Ms eyes. 

Since then the moles have had to h'?;e in dark places and unless one looks 
very closely he con noi find ^/leir eyes. 

Method. — Provide *S with a demonstration or practise text 
(either one of the three regular texts not to be used subsequently, 
or the special sample prepared by E). Explain the nature of the 
test, in accordance with the directions printed on the test-blanks. 
It is well, in addition, to suggest that, in case a certain eUsion offers 
special difficulty, it may be temporarily passed by, since the correct 
interpretation of the context further on will often give the needed 
cue for the omitted elision. 

When it is clear that *S understands the conditions, proceed with 
the test proper. Use either Text No. 1 or Text No. 2, or both suc- 
cessively, and record >S's time with the watch. 

Make notes of the manner in which S undertakes the test. 
Does he read it all over at first? Does he work systematically? 
Attentively? With confidence or hesitation? Does he grasp the 
general thread of the story? 

Variations of Method. — (1) To conduct the test with the 
memory feature, employ Text No. 3, which is specially devised for 
that purpose. After the preliminary trial, read the unmutilated 
text for No. 3, entire, to S. Then supply him with the No. 3 
test-blank and proceed as before. The text may be read more than 
once, or any desired time-interval may be introduced between 
the reading and the execution of the completion. Other variations 
will suggest themselves, e.g., auditory, visual, or auditory-visual 
reading, etc. 

(2) For group tests, use either of the methods just described. 
Limit the time so that the fastest S in the group tested can but 
just complete the work. For adults, seven minutes may be em- 
ployed for the first two texts, a shorter time for the third. Group 
tests, for the reasons already given, are not to be recommended: 
it is better to allow each >S to complete the entire test. 



450 IMAGINATION AND INVENTION 

Treatment of Data.- — In the individual form of procedure, 
rapidity of work may be measured in terms of elapsed time, accu- 
racy by the percentage of 'completions' that 'make sense' and that 
do not violate the instructions. For net efficiency, speed and 
accuracy might be reduced to a single numerical symbol, after the 
methods suggested in the Cancellation Test. For mature ^S's, 
working individually with the texts here used, the quality of work 
will commonly be very high, so that speed of work itself may be 
used as an index of efficiency. 

As used by Ebbinghaus, Krueger and Spearman, and others, 
however, the time-limit method has been followed, with an allow- 
ance, for the German texts, of 4 or 5 minutes. In this case, 
quantity and quality of work arc computed as follows: (1) Give a 
credit of 1.0 for each elision filled in in any manner. (2) Give 
a debit of 0.5 for each elision unfilled in any manner. (3) Give a 
debit of 1.0 for each elision filled in such a manner as not to make 
sense, or for each word introduced in excess of the number called for 
by the lines that indicate elisions (or for each word that is quite 
obviously too short or too long for the space assigned for comple- 
tion, even though the passage 'makes sense'). For quantity of 
work done, add (2) and (3) and subtract the sum from (1). For 
quality of work done, compute the relation in per cent of the same 
svnn to (1). 

Typical Results. — The following is a sample of the work of 
a boy, 11 years old, one of Terman's "bright" group, who 'com- 
pleted' the second text, with the exception of three elisions, in 26 
minutes. He was quick, steady, and looked ahead. 

"One day an eagle went with the other birds to see who could fly the 
highest . . . (Next three sentences correct) . . . When he came back the 
others were waiting for him; and when he touched the ground a linnet flew off 
his back where the thief had hidden and said that he himself was the strong- 
est bird. "I am stronger than you are," said the linnet, "for not alone did 
I fly as high, but as he began flying downward, then I left my hiding place 
and flew up a little higher," etc. 

The following is a sample of the work of a boy of the same age, 
one of Terman's "stupid" group, who worked for 25 minutes at 
the same text. Save in one or two easy sections, his 'comple- 
tions' make no sense at all. He worked by phrases only. 



TEST 48: EBBINGHAUS' COMPLETION METHOD 451 

"One with the eagle and with the small birds and see who could fly the 
highest, and agreed and he who will fly the highest should be called the 
strongest they All started in the same place and whent away among the 
clouds . . . After a while he decided that the king of the little bird and 
not only and he was so high, but he did the thing as well," etc. 

General Results and Conclusions. — (1) Performance in the 
completion test, as would be expected, improves noticeably with 
age. The results of Ebbinghaus are shown in Table 93. 

table 93 
Dependence of the Completion Test on Maturity {Ebbinghaus) 



SCHOOL GRADE AVERAGE NUMBER SYLLABLES | AVERAGE PER CENT OP ERRORS 

Untertertia 69 10 

Quartal. 49 17 

Quinta 46 26 

Sexta 32 33 



Wiersma, however, was able to differentiate the relative influ- 
ence of mere age, or maturity, and degree of school training (Ent- 
wickelung), and he then found that, while some correlation existed 
between age and performance in this test, a much greater correla- 
tion could be demonstrated between school training and per- 
formance (of children of the same age, those do better who are in 
higher classes), so that the table just quoted from Ebbinghaus may 
be looked upon as, in the main, a demonstration of this latter corre- 
lation. 

(2) According to Wiersma, sex differences can not be made out 
with certainty. 

(3) Practise may, according to Wiersma, effect an improvement 
in efficiency in the completion test that may be easily discerned 
after the lapse of 10 days, and even after an interval of 6 weeks. As 
a consequence, it is evident that, in making use of this test for 
comparative work at different periods, steps must be taken to 
eliminate or compute the practise-effect. 

(4) In Ebbinghaus' Breslau investigation, no fatigue effects 
could be made out as the result of the five-hour session in the case 
of the upper classes, or at least, if fatigue were present, it was over- 



452 IMAGINATION AND INVENTION 

balanced by practise: in the lower classes (10-12 years), however, 
the presence of fatigue was demonstrated. 

It seems evident that the texts emplo3'ed by Ebbinghaus were too easy 
for some of the upper classes tested by him: the effect was, naturally, to 
obscure the influence of fatigue and other factors. 

Wiersma compared performance before and after a 10-days vacation, 
but he expresses his belief that the marked improvement exhibited by the 
pupils at the second test was largely due to practise. It is unfortunate 
that proper measured have been not taken to eliminate the practise error 
in these, and in other applications of the completion test. 

In the opinion of Kraepelin, the Ebbinghaus test is to be regarded more 
as a device for exploration than as a decisive and accurate device for meas- 
uring fatigue, for, in the first place, no systematic study has yet been made 
of the relations between mental fatigue and the complex activities concerned 
in this test, and secondly, the evaluation of the errors is so diflBcult and 
their scoring so arbitrary that the test is not well designed for single appli- 
cations (Stichprohe) and statistical treatment. 

(5) The correlation with intelligence is, according to Ebbing- 
haus, clearest in the lower classes, and progressively less clear as 
the higher school grades are reached. When the Breslau pupils 
were divided into three groups — best, average, and poorest — 
on the score of class standing, their average rank was, in terms of 
quantity of work, 56, 48, and 43, respectively, and in terms of 
quality of work (percentage of errors), 17.3, 20.8, and 26.3 per cent, 
respectively. 

Wiersma confirmed the existence of a correlation between 
capacity in the completion test and native ability (Begabung), 
both in tests at a teachers' seminary (ages 14.5 to 19.5) and at a 
continuation school (ages 12 to 15). 

The author, however, has found no correlation between ability in 
this test (Text No. 1) and the class standing in psychology of 45 
college students. 

Ebbinghaus believes that the correlation between the completion test 
and intellectual ability may become obscured (1) because the test puts a 
premium upon speed of work, whereas the school grade is based on work 
that permits of a slower pace; (2) because, in some part, standing in the test 
may depend upon purelj' formal linguistic skill or verbal dexterity — a form 
of ability which, he thinks, has but a limited scope in school work, and (3) 
because the text selected for the test may be too easy. 



TEST 48: EBBINGHAUS' COMPLETION METHOD 453 

In the author's opinion, these reservations are scarcely in order, in so 
far as Ebbinghaus implies that school grades are inferior to his test as a 
measure of intellectual ability and asserts that linguistic readiness plays 
no part in the determination of school grades. 

The author is inclined, rather, to agree with Terman when he says : "My 
experience with the test causes me to regard it favorably ; but, like all others, 
if taken alone, it can give only a partial account of the subjects' ability. 
It certainly does indicate something as to the general command of language. 
I am inclined to think that somewhat mechanical activities like memory 
and association, as distinguished from synthetic or combinative processes, 
play a relatively more important role in this test than Ebbinghaus assigns 
to them. Indeed, verbal memory, in the broad' sense, would seem to be 
the chief factor in success." Incidentally, ability to spell, degree of famil- 
iarity with the type of literature from which the selection is taken, and the 
way in which S happens to go about the test may all affect his rank. In- 
deed, it is possible that a very original S, one with a spark of literary inven- 
tion, might fare relatively poorly. 

(6) Other correlations, as determined by Krueger and Spearman, 
are as follows: completion test and pitch discrimination, 0.81; 
completion test and adding, 0.93; completion test and the hypo- 
thetical 'central-factor,' 0.97.^ The completion test has no corre- 
lation with a test of memory span (Auswendiglernen) . The ex- 
tremely high correlation with the 'central-factor' is of special inter- 
est, since it demonstrates a very close dependence of performance 
in this test upon a certain hypothetical psychophysical capacity, 
presumably akin to plasticity of the central nervous system, 
which, in the opinion of these authors, is, for each individual, a 
fundamental conditioning factor in the performance of various 
forms of mental activity. 

Notes. — It is evident that the outcome of the completion test 
hinges largely upon the degree of difficulty of the text employed : 
too difficult or too easy texts are alike undesirable, for the former 
convert the test into a blind puzzle, Vv'hile the latter fail to bring 
out characteristic individual differences of ability. 

To use the test on an extensive scale, therefore, we need to have 
at hand a number of texts that have been standardized by compre- 
hensive trials with groups of S's of both sexes, various ages, and 

' These correlations are 'pure' correlations, computed from 'raw' correla- 
tions by the use of corrective formulas such as have been described in Ch. 
Ill, pp. 41-44. 



454 ' IMAGINATION AND INVENTION 

various degrees of capacity and training. In other words, we need 
a series of norms of performance, or ' coefficients of difficulty,' as 
it were, for an adequate number of prescribed texts. 

The difficulty of making comparisons between the results of 
different texts applied at different times may be further reduced by 
always permitting each S to finish each text, and by distributing 
the texts to be compared, in such a manner as to eliminate by subse- 
quent computation whatever error arises from this difference of 
material. 

The Lipmann-Wertheimer modification of the completion 
method is essentially as follows : a test-story is read to S to supply 
him with certain information which he is supposed thereafter to 
conceal. He is subsequently given for completion a mutilated 
text, the elisions of which are so arranged as to trap him into intro- 
ducing facts from the test-story which he is trying to conceal. 

KEFERENCES 

(1) H. Ebbinghaus, Ueber eine neue Metliode zur Priifung geistiger 
Fahigkeiten und ihre Anwendung bei Schulkindern, in Z. P., 13: 1897, 401- 
459. 

(2) T. Elsenhans, Nachtrag zu Ebbinghaus' 'Kombinationsmethode,' in 
Z. P., 13; April, 1897, 460-3. 

(3) E. Kraepelin, Ueber Ermlidungsmessungen, in A. 'G. P., 1: 1903, 
9-30, especially 17. 

(4) F. Krueger and C. Spearman, Die Korrelation zwischen verschiedenen 
geistigen Leistungsfahigkeiten, in Z. P., 44: 1907, 50-114. 

(5) O. Lipmann and M. Wertheimer, Tatbestandsdiagnostische Kombi- 
nations-vervSuche, in Zeits. f. angew. Psych., 1: 1907, 119-128. 

(6) M. Meyer, An English equivalent of "Combinationsmethode," in 
Jour. Phil., Psych, and Sci. Meth., 9: 1909, 688. 

(7) L. Terman, Genius and stupidity, in Pd. S., 13: Sept., 1906, 307- 
373, especially 342-7. 

(8) E. Wiersma, Die Ebbinghaus'sche Combinationsmethode, in Z. P,, 
30: 1902, 196-222. 

TEST 49 

Interpretation of fables. — E. J. Swift has suggested that 
mental ability may be measured by determining the capacity to 
interpret the total situation given in a typical fable. Swift's 



TEST 49: INTERPRETATION OF FABLES 455 

three test-fables have been also emplo}' ed by Ternian, in addition 
to 12 other fables, in his study of the comparative efl&ciency of 
bright and stupid children/ 

Material. — The following are the three fables used by both 
Swift and Terman. 

Fable 1. 
The Boy and the Filberts. 

"A boy once thrust his hand into a pitcher nearly filled with 
filberts. He grasped as many as his hapd could possibly hold; but 
when he tried to draw out his closed fist, the narrowness of the 
neck prevented him from doing so. Unwilling to lose his nuts, yet 
unable to get them by drawing out his hand, he burst into tears 
and bitterly lamented his hard fortune." 

Fable 2. 
The Horse and the Rider. 

"A cavalry ofl&cer took the greatest of pains with his horse. As 
long as the war lasted, the horse Avas looked upon as a companion 
and fellow-helper. He was carefully groomed every day and fed 
with oats. 

But when the war was over, the allowance of grain and hay 
ceased, and the horse was fed with chaff, and whatever he might 
find by the wayside. He was made a drudge, too, and often forced 
to carry loads much too heavy for his strength. 

When, in course of time, war was again proclaimed, the soldier 
brought his militarj'- trappings, and put them on his horse; and, 
after putting on his own coat of mail, he mounted to ride to battle. 

But the horse, no longer equal to the burden, fell down straight- 
way under the weight." 

Fable 3. 
The Fishes and the Pike. 
"The fishes in a pond brought an accusation against the pike 
who were eating them up. The judge, an old pike, said that 
their complaint was well founded, and that in the future, to make 
things right, he would allow two ordinary fish every year to be- 
come pike." 

' The details of these 12 fables are not published, but the reader may form 
an idea of their nature by consulting Terman's original article. It would 
seem desirable that further tests should be made in order that a series of 
test-fables of varying difficulty might be standardized by application to 
large groups of normal children of various ages. 



456 IMAGINATION AND INVENTIOJN 

Method. — Read the first fable to *S. Ask him then to tell what 
he thinks of the boy, and why he thinks so. Use a few discreet 
questions, if necessary, to be positive as to his interpretation of the 
story. Record his statements verbatim. Continue the test by 
reading Fable No. 2, and asking S what he thinks of the cavalry 
officer and why. Similarly, ask his opinion of the plan of "Judge 
Pike." 

Variations of Method. — So far as the mechanics of method are 
concerned, this test may be conducted with groups of *S's by using 
written answers, but it appears evident from the results that this 
method is to be avoided whenever possible. 

Treatment of Data. — >S's standing must be determined by 
observation of the readiness with which he offers an interpretation 
to each fable, and by the soundness and excellence of this inter- 
pretation. For quantitative comparison, E will find it advisable 
to assign the rank 5 for a perfectly satisfactory answer, 1 for a 
complete failure to 'see the point,' and intermediate grades in 
proportion. For a final score, add the rank obtained by S in each 
of the three trials. 

Typical Results. — Terman quotes the following 'interpreta- 
tions' of Fable 3. Sample of a 'good' answer (Grade 5): "Not 
fair." (Asked why) "Because the more pike there became, the 
faster they would eat the little fish." Sample of a very poor answer 
(Grade 1) : " It might be better for the little fish in some ways — they 
would not be eaten up." Sample of answer of medium quality 
(Grades) : "That was all right, but then if only two are changed to 
pike, the others would get eaten up." 

Results. — (1) Correlation with school proficiency. Swift reports 
that the fable-test showed no superiority for the 'bright' children; 
that, on the contrary, in Fable 3, which, he says, requires "a dis- 
tinctly intellectual process," the dull group excelledthe bright group, 
while the answers of boys in an industrial (reform) school "dis- 
tinctly outranked those from both of the other groups, but especi- 
ally the ones from the ' bright' division, in the penetration and ver- 
satility that they showed." 

Terman's tests showed, on the contrary, that his 'dull' group 
was distinctly inferior to his 'bright' group, for, as he says: "in 
the first place, they more frequently miss the point of the story 



TEST 49: INTERPRETATION OF FABLES 457 

altogether," and "in the second place, the dall boys are plainly 
deficient in degree of abstraction. Even when they give an approxi- 
mately correct interpretation, they usually express it in the con- 
crete terms of the given situation, instead of generalizing it," 
e.g., the following answer for Fable 2: "It teaches a man when he 
has a horse to keep it and use it well." 

This lack of accordance is attributed by Terinan to some fault in method 
on the part of Swift. "I should judge," he says, "that his results would 
have been different if he had been able to take his cases individually, in- 
stead of collectively." 

By way of illustration, the following quantitative results may be quoted. 
Swift reports that, with Fable 3, 27% of his 'bright' group, as contrasted 
with 9% of his 'dull' group, thought the plan wise and just. Again, only 
15% of the bright children, as contrasted with 30% of the dull children, 
pointed out that the plan w^ould not help the fishes that were not turned 
into pike. When scored according to Terman's plan,i his bright >S's averaged 
for Fables 1, 2 and 3, the ranks 1.3, 3.17, and 2.83, respectively, while his 
dull fS's averaged the ranks 1.86, 4.57, and 4.57 for the same three fables. 

(2) Dependence on age. Terman suggests that "what is tested 
by the interpretation of fables is, in part at least, that general 
change of mental horizon that comes with increased experience 
and dawning maturity." In other words, the outcome of the test 
is conditioned, as one might have expected, by age and experience, 
as well as by native abihty. 

(3) Types of replies. Swift states that "the answers from the 
public school children lacked individuality : they were conventional, 
while those from the reform school gave evidence of spontaneity 
and resourcefulness," and he draws from this the dubious conclu- 
sion that "the question may be seriously raised whether the schools 
do not train children to stupidity." 

REFERENCES 

(1) E. J. Swift, Standards of efficiency in school and in life, in Pd.S., 
10: 1903, 3-22,' especially 3-6. 

(2) L. M. Terman, Genius and stupidity : a study of some of the in- 
tellectual processes of seven 'bright' and seven 'stupid' boys, in Pd. S., 
13: 190G, 307-373. 

' Terman gave the score 1 for a satisfactory answer, 5 for a complete fail- 
ure. 



CHAPTER XII 

Tests of Intellectual Equipment 

The tests of this chapter differ from other mental tests described 
in the present volume in that they measure, not the efficiency witji 
which certain typical mental activities or mental processes can 
function, but rather the number of ideas that an individual pos- 
sesses. In other words, their purpose is not to measure what the 
individual can do, or how well he can do it, but what he knows 
about — to take a census, as it were, of his stock of information. 
G. Stanley Hall's study of the content of children's minds on 
entering schooP is, perhaps, most nearly allied in type and concep- 
tion with the tests which are here presented. 

The first test is designed to secure an estimate of the number of 
words in the reading vocabulary of the individual tested, the 
second to secure an estimate of the number of subjects (disciplines, 
phases of human activity) with which the individual has an exact 
or an approximate acquaintance. 

TEST 50 

Size of vocabulary. — Since nearly all thought and expression 
is couched in linguistic form, and since the intellectual progress of 
the child at school is, in a sense, a process of augmentation of his 
vocabulary and of refinement in its use, it seems not unreasonable 
to assume that the determination of the size of this vocabulary 
will be of significance and value in estimating his general intellec- 
tual status. 

Experiments conducted by Kirkpatrick have shown that an 
approximate determination of what might be termed the vocabu- 
lary-index can be secured by the use of the relatively short and 

"See his Aspects of child life and education, Boston, 1907. 



TEST 50: SIZE or vocabulary 459 

simple test that is described herewith. By extending the tests, 
the usual comparative study may be made, and the index may be 
related to its conditioning factors — age, sex, school standing, 
extent of reading, general ability, etc. 

This test has, up to the present date, been applied only by the 
originator, Professor Kirkpatrick, and by the author, though with 
some variations of method. 

Material. — Printed list of 100 words, as employed by Kirk- 
patrick and by Whipple. 

Preliminaries. — In accordance with Kirkpatrick's plan, several 
preliminary exercises are employed, in order, on the one hand, to ob- 
tain data with regard to ^S'sgeneralfamiliarity with words, his range 
of reading, etc., and on the other hand, to instill in him an attitude of 
caution in undertaking the vocabulary-test proper. These pre- 
liminary exercises are as follows:' 

(1) Ask S to write the opposite of the following terms : good, long, 
break, rude, simple, permanent, particular, permit, obnoxious, genuine. 

(2) Ask S to tell (orally or in writing) what the following words 
mean : abductor, baron, channel, decemvirate, eschar, amalgamation, 
bottle-holder, concatenate, disentomb, filiform, gourd, intercede, mat- 
ting, page, hodman, lanuginose, muff, photograph, scroll, tycoon. 
(Where words have more than one meaning, all are to be given.) 

(3) Secure from 8 a list of all the papers and magazines that he 
is in the habit of reading. 

(4) Secure from S the names of the books that he has read dur- 
ing the past 6 months. 

(5) Ask 5 which of these books he liked best, why he liked it, 
and to give some account of what it was about. 

(6) Ascertain the birthplace of >S's parents, his school grade, and 
his favorite school subjects. 

Method. — Hand to *S the printed test-slip: ask him to read the 
instructions and to mark the words carefully in accordance with 
them. 

Treatment of Data. — The number of 'plus' marks indicates 
the vocabulary-index in terms of per cent of words known. The 



' To follow the plan, the first two exercises, at least, should be given when- 
ever grade pupils are tested, and all five if time permits. 



460 



INTELLECTUAL EQUIPMENT 



absolute vocabulary is then computed, following Kirkpatrick, 
by assuming the total number of words in the language (Web- 
ster's Abridged Dictionary) as 28,000, 

Variations of Method. — To study S's tendency to overesti- 
mate or underestimate his vocabulary, E may follow the plan 
used by the author with college students, of giving the check-defi- 
nition test after the vocabulary-test. 

(1) Give *S the vocabulary test without suggesting that he may 
be called upon to justify his marking. 

(2) When the marking has been completed, and the slip is in 
E's hands, submit to S the following list of words, with a request 
that each word be defined. Allow 20 min. for written definitions. 





Definition-list.' 




abductor 


interdict 


amalgamation 


lanugo 


abet 


interim 


amanuensis 


lanyard 


baroscope 


mattock 


amaranth 


mufti 


chanticleer 


maturate 


bottomry 


photo-lithograph 


chaos 


pudgy 


concatenate 


rejoinder 


decern virate 


scruff 


disentrance 


skysail 


eschar 


scrunch 


disepalous 


tendinous 


escheat 


subcutaneous 


disestablish 


tendril 


eschalot 


tycoon 


filiform 


virago 


gourd 


tymbal 


hoecake 


virescent 



Treatment of Data. — For each S, ascertain from the defi- 
nition-test: (1) the number of words not defined, (2) the number 
of words wrongly defined. (3) Add these to find the total number 
of words unknown in the list of 40. (4) Consult the vocabulary 
test-slip to see whether any words outside the list of 40 are marked 
unknown.^ (5) Consult the vocabulary-slip again to see whether 
any words thereon are marked doubtful and have not been cleared 
up by the definition-test: consider these as unknown. (6) Add 
all the unknown terms to determine the final corrected vocabu- 



' Concatenation, lanuginose and lanuginous, of the vocabulary-test, can; 
of course, be checked off by the definitions given for concatenate and lanugo. 

^ In a test of Sophomores and Juniors in college, we were surprised to 
find the following words in this category: barque, barouche, boudoir, disen- 
tomb, filigree, hodman, pagoda, rejuvenate, scroll, sub-let, tenderloin. These 
words, then, it seems, would have to be added to the 40 to secure a compre- 
hensive list of possibly unknown words. 



TEST 50: SIZE OF VOCABULARY 



461 



iary-index. (7) Compare this index with the index indicated by 
S on the vocabulary-shp to see whether S has over- or underesti- 
mated his vocabulary, and to what degree. 

Results. — (1) Kirkpatrick's computation of the average vocabu- 
lary is shown in Table 94. The author's results, based on 70 college 
students (16 men and 54 women), aged 16 to 25 years, indicate 
an average vocabulary of 21,728 as based on the uncorrected esti- 
mates of the students, and of 20,512 as based on the corrections 
supplied by the supplementary definition-test.' 

table 94 

Average Vocabulary in Relation to Scholastic Status (Kirkpatrick) 



SCHOLASTIC STATUS 


VOCABXJLART 


SCHOLASTIC STATUS 


VOCABULABT 


Grade II 


4480 


Grade IX 


13,400 


Grade III 


6620 


High school, 1st year 


15,640 


Grade IV 


7020 


High school, 2d year 


16,020 


Grade V 


7860 


High school, 3d year 


17,600 


Grade VI 


8700 


High school, 4th year 


18,720 


Grade VII 


10,660 


Normal-school pupils 


19,000 


Grade VIII 


12,000 ■ 


College students 


20,120 



(2) In the author's definition-test, no word of the 40 was correctly 
defined by every student, and since, as has been noted, there 
remained 16 other words that were unknown or doubtful, it 
follows that only 44 of the 100 words in Kirkpatrick's list were 
certainly known by every one of 70 college students. 

(3) There is wide individual variation in the size of the vocabu- 
laries of students of the same age and scholastic status. This 
variation is shown by the distribution in Table 95. The largest 
college-student vocabulary found by the writer is 24,920 (89 per 
cent); the smallest is 16,240 (58 per cent), or approximately the 
vocabulary assigned by Kirkpatrick to the average 2d-year high- 
school pupil. 

(4) No positive sex differences have been estabhshed, though 



' For the size of the vocabularies of children up to 4 years of age, consult 
Whipple (5), where there will be found a summary of the results of numer- 
ous investigations. 



462 



INTELLECTUAL EQUIPMENT 



TABLE 95 
Distribution of Corrected Vocabulary-Index. 70 College Students (Whipple) 



INDEX 


55-59 


60-64 


65-69 


70-74 


75-79 


80-84 


85-89 


No. of cases 


1 


6 


13 


22 


19 


5 


5 


Highest index, 89%. Average index, 73.26%. Lowest index, 58%. 



there is a suggestion of superiority of boys over girls, and of men 
over women. 

(5) In general, pupils that read the most books and magazines 
have the largest vocabularies. 

(6) Kirkpatrick found a tendency toward positive correlation 
between class standing (teachers' grades) and vocabulary-index: 
"those ranking high in scholarship knew on an average about 
5 per cent more words than those ranking low in scholarship." 
The author found a more decided correlation (r = -\- 0.45, P. E. 
= 0.06) between the index of 58 college students and their grades 
in his classes in educational psychology. 

(7) When no precautionary measures are taken to offset the 
tendency, the determination of the vocabulary-index is commonly 
affected by over estimation. Inspection of Table 96 will show that 
59 of the 70 college students examined by the author overestimated, 
while but 10 underestimated their vocabulary: the largest over- 
estimation was 18 per cent; the largest underestimation was 4 
per cent. Since 20, or more than i of the students overestimated 

TABLE 96 
Overestimation of the Vocabulary-Index. 70 College Students (Whipple) 



PER CENT OVEHESTIMATBD 


NUMBER 


PER CENT OVERESTIMATED 


NUMBER 


18 


1 


5 


7 


15 


2 


4 


6 


14 


3 


3 


. 7 


13 


1 


2 


10 


12 


3 


1 


9 


11 


1 





1 


9 


• 2 


—1 


6 


8 


2 


—2 


2 


7 


1 


—4 


2 


6 


4 







TEST 50: SIZE OF VOCABULARY 463 

by 5 per cent or more, it is evident that, without a somewhat 
elaborate definition check, the rehabihty of the vocabulary-test 
is distinctly lessened.^ 

(8) The definition-test reveals an unexpectedly large number of 
erroneous definitions. The source of these errors may frequently 
be traced to confusion with words of similar appearance or to fancied 
etymological derivations. The following list shows typical errors 
in definition by college students : the assumed source of confusion 
is indicated by the terms in parentheses after the definitions : 

amanuensis — poet laureate, lovingness (amativeness). 

amaranth — a precious stone (amethyst). 

abet — although (albeit), a wager (a+bet), diminish (abate). 

bottomry — the art of bottoming chairs, deceit, bottom of anything. 

chanticleer — one who sings a loud song, one who leads a chant. 

decemvirate — composed of five, count out by tens, formerly a group of 
ten men, but any number now. 

disentrance — failure to enter. 

disepalous — apart from the head, without shoulders. 

gourd — reward (guerdon), to slash or whip (goad), morning glory. 

interim — time between two reigns (interregnum) . 

lanugo — a kind of language. 

lanyard — yard where leather is tanned (tanyard), yard about the lane. 

mattock — a lock of hair (matted locks?), a kind of bird, a sort of rug, a 
kind of robe (cassock). 

maturate — to ripen (mature), to matriculate. 

sky-sail — a sail in the sky, a kite. 

tycoon — a violent wind (typhoon), an animal, a silk-worm, a natural 
phenomena (sic). 

tendril — a membrane connecting two bones (tendon). 

tendinous — capable of endurance (tenacious?). 

scrunch — a good for nothing person (scrug?). 

virago — a kind of bird (!) (vireo), a disease, giddiness (vertigo). 

virescent — sparkling (iridescent), of or pertaining to man (!) (virile). 

Notes. — (1) The greatest source of unreliability in the vocabu- 
lary test lies in individual differences in the subjective standard 

' This result may be compared with Kirkpatrick's conclusion that very 
young children are apt to underestimate because the isolated words of the 
list fail to arouse associations such as they would if they had a context. 
Again, when Kirkpatrick defined the words of the list to normal-school 
students, he found that the errors of over- and underestimation tended to 
cancel one another; while, when college classes defined 20 words, 114 of 246 
students (about 46 per cent) correctly defined the same proportion that they 
had marked as known, and only 7 per cent erred by as much as 3 in 20. 



464 INTELLECTUAL EQUIPMENT 

employed by different >S's in marking their lists: some S's mark, 
as known, words which are little more than familiar; others mark 
words as known only when they can define them accurately. 
Kirkpatrick suggests that, to minimize this source of error, the 
directions might be amplified as follows: "Count as known all 
words whose meaning would be known, without consulting a 
dictionary, when read in a sentence." 

(2) This leads one to say again that, especially in the case of 
young children, there may be a tendency toward underestimation 
of the vocabulary because isolated words sometimes fail to arouse 
the interpretative meanings that they would arouse at once in their 
customary context. In so far as appeal to the ear as well as to 
the eye is of assistance to young children whose vocabulary is 
largely auditory, this source of error might be partially offset by 
reading the list aloud to them. 

(3) In grading the definition-test, it is at times rather diffi- 
cult to decide from the definitions whether S does, or does not 
know the meaning of a word with sufficient exactness to be credited 
with knowledge of the term in question. In general, it is better, 
in consideration of the difficulty of accurate definition and of the 
short time usually available for this part of the test, to err on the 
side of leniency. 

Thus the following definitions might be accepted: 'disestablish — to 
overthrow,' ' decern virate — a body of ten,' 'mattock — a garden tool,' 
'amaranth — a flower;' while the following ought, in our opinion, to be dis- 
allowed: 'lanyard— one of the spars of a ship,' 'decemvirate — Roman civil 
officer,' 'gourd — a hollow vessel from which to eat and drink,' 'concatenate 
— to argue,' 'baroscope — an instrument for measuring something.' 

REFERENCES 

(1) E. H. Babbitt, A vocabulary test, in Pop. Sci. Mo., 70: 1907, 378. 

(2) E. Kirkpatrick, Number of words in an ordinary vocabulary, in 
Science, 18:1891, 107-8. 

(3) E. Kirkpatrick, A vocabulary test, in Pop. Sci. Mo., 70: 1907, 
157-164. 

(4) G. M. Whipple, Vocabulary and word-building tests, in P. R., 15: 
1908, 94-105. 

(5) G. M. Whipple (and Mrs. Whipple), The vocabulary of a three- 
year-old boy, with some interpretative comments, in Pd. S., 16: 1909, 1-22. 
(Contains references to 27 articles on children's vocabularies.) 



TEST 51: RANGE OF INFORMATION 465 

TEST 51 

Range of information. — The words that comprise Kirkpatrick's 
vocabulary test are intentionally selected by chance: some of 
them, like page, happen to be most ordinary and everyday terms; 
others, like lanuginose, are unusual, technical terms. The extent 
of S's acquaintance with words of the latter kind depends 
almost entirely upon the nature of his school training, or upon 
the quantity and type of his general reading. 

The range of information test has been devised by the author 
as an extension of the vocabulary test. The hundred test-words 
have been selected, not by chance, but by careful consideration, 
and in such a manner that each shall be representative of some 
specific field of knowledge or activity, in the sense that if S has 
made himself familiar with a given field, he wdll almost certainly 
know the word selected from that field, whereas if he has not made 
himself familiar with the field, he will almost certainly not know 
the term, or at least will not have such knowledge of it as to enable 
him to define it exactly. Thus, general knowledge of American 
history is tested by the name Anthony Wayne, knowledge of 
French by aujourd'hui, of chemistry by chlorine, of ethics by 
hedonism, of golf by midiron, of social usages by R. S. V. P., 
of the technique of photography hyf-6/f, etc. 

Material. — Specially prepared test-blank containing 100 test- 
words, directions for marking them, and a request for 10 defini- 
tions. 

Method. — Place the blank in S's hands: ask him to read the 
directions through twice before marking the words, and call his 
attention to the request for definitions as printed below the test- 
words. Let him take his own time. 

For exact results, S should afterward be required to define 
every word that he has marked D, and to explain or attempt to 
explain every word that he has marked E or F. This check test 
should, by preference, be conducted orally. In practise, however, 
especially when testing by the group method, such careful checking 
may prove too onerous: erroneous definitions may then be neglected, 
or the quantitative data may be revised by discounting on the 
basis of the percentage of error revealed in the definitions actually 



466 



INTELLECTUAL EQUIPMENT 



given. Or, again, E may, after the test is concluded, define the 
100 words, and let each S revise his own paper by placing a second 
series of marks after each word to indicate the manner in which 
he should have marked it. A comparison of the sums of the D's, 
E's, F's and iV's of the first, and of the second series will then 
show approximately'- the extent and nature of the error due to 
ignorance or misunderstanding of the real meanings. 

Results. — (l) T3;pical quantitative results, as obtained by the 
author from some hundred cases, are embodied in Table 97. Here 
it is evident that advance in school training, together, of course, 
with increased maturity, is paralleled by an increase in the number 
of technical terms that can be defined (F), explained (E), or that 
are at least familiar (F), and by, of course, a corresponding decrease 
in the number of terms that are new or unknown (iV) . 



table 97 
Dependence of Range of Information on Academic Status (Whipple) 



ACADEMIC STATUS 


NUMBER 


"^ 


E 


F 


N 


Graduates 


4 


39.0 


21.0 


12.2 


27.0 


Seniors 


5 


20.6 


17.2 


25.2 


37.0 


Juniors 


10 


24.8 


12.0 


23.7 


39.5 


Sophomores 


30 


17.7 


12.7 


17.3 


52.2 


High School 


52 , 


6.8 


7.6 


16.3 


69.3 



(2) Comparison of the sexes indicates the superiority of the 
range of information of men and boys over women and girls, as 
is indicated in Table 98. 

table 98 

Dependence of Range of Information on Sex {Whipple) 



Men 
Women 



15.79 
12.21 



11.98 
9.42 



18.22 
17.19 



54.02 
61.17 



(3) The results just figured are 'raw' results: strictly speaking, 
these should be revised on the basis of an extended series of defini- 
tions, as recommended in the Vocabulary Test, since an inspection 



TEST 51 : RANGE OF INFORMATION 487 

of the definitions and explanations actually given reveals in the 
majority of the papers one or more errors, due in the main to 
confusion with words of similar appearance or to fancied etymolog- 
ical derivations. The following list shows t^-pical errors in defini- 
tion by college and high-school students: the assumed source of 
confusion is indicated by the terms in parentheses after the defi- 
nitions : 

ageratum — an aggregation of objects: the aggragate (sic) amount. 

annealed — pressed or rolled out thin: molded together. 

Anthony Wayne — a historic character who was hung in the cause of free- 
dom for the blacks : a man who fought in the Revolution on the English side. 

Babcock test — a device to ascertain whether or not cattle have tuber- 
culosis. 

base-hit — when the ball is hit and strikes a base or is caught there : a ball 
batted over a base: when the striker bats the ball into the pitcher's hands. 

Bokhara — name of a place in Austria. 

cantilever — a bar with a hook in one end by which lumbermen roll logs 
(canthook). 

catalepsy — a form of disorder of the nervous system which causes fits or 
convulsions (epilepsy). (Similar statements given by 15 persons.) 

chamfer — the tree from which camphor gum is obtained: this is the sim- 
plified spelling of it (!) , (The confusion with camphor was found in 4 papers.) 

clearing-house— a sale that takes place when a store wishes to dispose of 
its stock (clearing sale) : a place where clearing papers are given to vessels 
to enable them to leave the harbor (customs house -|- clearing of vessels) : 
picking up everything to move; taking everything out of the house : a place 
used by express companies to sell uncalled-for goods: a house where goods 
are made ready to be delivered. 

cotangent — name of one of two tangents drawn to a circle from the same 
point without the circle: one lying alongside of (contingent): straight line 
drawn to touch a circle at one point (tangent). 

dibble — to get just a smattering of some subject, as to dibble in medicine 
or politics (dabble) : to do with divided interest (dawdle) . 

dryad — a priest of early English times (druid). 

entree — first course at a banquet, usually soup: something in the way of 
food, new and out of season: when the waiter brings in a new course it is 
called an entree: French for 'to-day' : French for 'between' (enire). 

Eocene — the term applied to one of the early ages of civilization. 

Euclid — a book written by Vergil (x^lneid) : name given to certain trees 
(eucalyptus) : an ancient Egyptian who studied geometry: name of an avenue 
in Cleveland, Ohio. 

/-64^means the temperature is 64 degrees above zero, Fahrenheit. 

f. 0. b. — cash on delivery (c. o. d.) : forward on board. 



'1()H iN'no(;iJO(!'rnAi, kqiiii'Mknt 

liydniulic proHH— ji kind of air-i)umi), ratlicr ooinpliciikul, oporuLcd by 
sucLioii and jjniHHiiro: a nincliinc! for wuHliinn dirl, from k<>I'I or from Htoep 
BloptiH (hydraulic! milling;): (lie force; willi vvliicii w.-Ucr fIowHii|)oii or a^ainHt 
a MiiriK, aw a paddlct wheel. 

imi)rcHsioniHm -wIkmi m, man imitaUiH the IooIih or acUonH of another: the 
art of exciting a,n imprcHHion. 

infusoria a(!lmmi(!al herb (infusion?). 

kih)Kram — thci f^nsatdst (piantity in the; metric; HyHtom : l''renc,h uKianureof 
(liHtuiKio (kih)m(iter): I'^nMuiii unit of licpiid measure: tlui wciKht of a 
cubo of water vvliose dimensionH nrci a kiU)m(!ter. 

LoH MiH<^ral)I(^H -a I''r(meh tragcidy written al)out tlic hist part of tiie I7tii 
century by Itacirui, one of the famouK l''renc,h writcun: l''r(Mic.li work written 
by (ieorKo Sand, author of !.(; Diabhi. 

linotype; the prodiu't of a (lertn.in method of m;d<inn |)rinlH from i)Iioto- 
KntphH. 

Milha a blind pcxst (Miltonj. 

natural Hchiotion— in nature; eaedi animid HCilectw itH nuite, ii, device for 
buihlinf? u|) a Htrongor race;. 

ohm -(J(irnuin word for uncle (Olwim). 

I'oloniuH a prominent ciiaracter in JuHuh (la-Har. 

pomohjgy the study of the p.ilin of tin; hand, used l)y fortum; tellers 
(palmiHtry). 

tort — French word for ugly (tors?). 

triple oxpauHion — the expanding of anything three times its normal size. 

Utopia — a silk fatitory. 

way-bill -a bill tluit is laiing considered. 

Zionism -sanu; as IJowicism. 

(4) A c.ompurison of scores iiumIc hy I (Ssiuumcrscssioii students, 
hi^rorc and iiricr i]\{) dofiniiioii l>y PJ of the 100 t(M'ms, shows the 
followhiR- Mvcriiftcs: fkst iiuirkiiij;-, D = 20.39, E = 14.77, F = 
18.39, N = 46.44; second nmrkiiig, D = 19.77, E = 20.22, F = 
19.55, N = 40.44. So far us tliesc (S's arc concerned, then, it 
appears tluit at first they had overestimated terms defmable and, 
more particnihirly, t(>rms unknown. The principal effect of E'b 
exphmations was to increase by ahont (> per cent tlie number of 
terms marked as explainable, and to decreiise by (> per cent the 
numl)er of terms marked as unknown. 



(i, M. Whipph-, A rauMie of inft)rmation tc^st, in !'. U., 1(1: l!»Oi), 347-351. 



(^TtATTMH X\\\ 

Sl';iUAIi (iKADI'M) 'I'k.S'I'S I'Olt I )l'; V Kl,< H'M I'lN'I'A I , l)lA(JN()SIS 

Tlio t(!sl-s whi(;li luivci Ixuai (IcsciilxMl in I lie, |)ni(M'(liii^^- cluipl.i'r.s 
jiro mainly of an iHohdvA (iliariiclcr, in I lie schmc; iliuX r.}u'\\ tcHl. has 
l)(!(!n devised iiideix^idcnUy, .-md Uicy arc; (l(!Ki>2;ii(Kl |)rinia,rily for 
Ui(! exainitiaiion of :ulidl,s or noini;i,l (children, 'riic. Icsl.s wliic-li 
iire described in Mic present eliapLfsr arc, on iJic (^onl i;uy, dcsij^ncd 
primarily to (Uitc^rniine the irunital insullic/iency or rcl.ardiition of 
backward and abnormal children, and thcjy are arranged systematic- 
ally, in a {graded series, SMcih that (iaeli test or ki'<>"|' "I tests reprt;- 
sents an advances in difliculty ov(!r its predec(!Ssor, while the serieH 
as a whol(! eort^^sponds to proti;r(!Ssiv(; st-.'ljijcs or dc^-rccs of nicntnl 
(l(!V(!lopm(!nt. 

There is no doubt but that, as M(!umann cont(!nds,' this idea 
of a i)rof:;ressive series of tests is of siji;nifi(;ance for tin; invcistif^a- 
tion of normal as wcsll as of abnormal children, {ind, in fact, iVnuvt 
and Simon iiave not limitcul tlu; us(! of tlujir s(;ri(!S of tests to ab- 
normal childnm, but hav(! sought to cstM.bJish standards of pcr-- 
formance for normal children as well.^ 

TEST 52 

De Sanctis' graded series. — Santc; d(i San(;tis, of the IJni- 
V(Tsil,y of Home, has soufi;ht to arran>i;e a gradcul s(!ri(!S of l,(!sts, 
which sli!i,ll be at once; simf)l(! and compreli(!nsiv(!, af)prH;abl(! to 

' I']. Mcuiriurin, VtyrlcHuudcn zur /'jinfahrun{/ in (lie ax/). I'mUmixjik, \., j). 

:v.n. 

^ Tfioro Ih, of course, no particular rcaHon wliy Uio tcHts rruuitiorKul in thia 
chapter Hliould b« tho only ),(!HtH urranKod in a ft,viu\('.il H(!ri(!H. Wliat Ih really 
ncKHJed, an we have already iuHisted, irt thai, all of the t(!HtH that an; drrHcrihed 
iti tliia hook, in ho far aw they prove of perrriari(!tit viduc;, Hhould, hy the <;ol- 
l!i,l)oratiori of in vcsHti^atorH, he ho Htandardized that we may Icmjw the tioijiial 
outeoiiK! of iivc.vy t(!Ht for children of all aj^CH, juHt an wo alnsady know 
th(! iiorniHfof all a^en, and the diHtribution by i)ercentile grad(!H, in moHt of 
th(! anthropometric toHfcs. 



470 DEVELOPMENTAL DIAGNOSIS 

any feeble-minded child from 7 to 16 years old, and so selected 
as to throw into relief the differences in the intellectual capacity 
of mentally defective children. 

Materials/ — Five wooden balls, 50 mm. in diameter, painted 
red, orange, yellow, blue, and green, respectively. Three wooden 
pyramids. Two wooden parallelopipeds. A set of 12 cubes 

A. ▲■▲■■_ A.HAAI 
■ AA.iH.ABHA.AB. 

.BAA.B.AB..B.B 
AA.BA.B..B.ABB 

BB.. .BAB. .ABA A 
.ABBB.A..B..B. 
.B..AA.BB.BB.A 
B.BA..AA.B.B.B 
AB.B.AA.B.B.AB 
B..B..AB...B.A 

Fig. 58. de Sanctis' form-test. 
About i actual size. 

ranging in size from 10 to 80 mm. A small black cube. Test- 
card of forms (Fig. 58). Stop-watch. Cardboard screen (or cloth 
cover). 

* It is unfortunate that de Sanctis gives little more than a sketchy de- 
scription of his materials and method. We have, therefore, followed God- 
dard in planning the material and in arranging the details of procedure. 



TEST 52: DE SANCTIS' GRADED SERIES 471 

Method. — General directions. See that the child is comfortable 
and happy, not fatigued, frightened, or ill. Make a pleasant game 
of the whole procedm-e. 

Introduce a pause of 40 sec. between No. 1 and No. 2, and a 
pause of 1 min. between the other tests. 

In the effort to catch *S's attention and to explain the tests to 
him, instructions and questions may be repeated till given thrice : 
if S then fails, he is considered to be incapable of passing the test — 
save that, if the failure seems to be due to a temporarily unfavor- 
able disposition, the entire series may be repeated several days later. 

No. 1. 

Put the five balls on a table. Say to S: "Give me a ball." 
Record with the stop watch the time taken by him in responding. 
Put the ball away at once, with the others, behind the screen. 

No. 2. 

Show the five balls again, and ask S: "Which ball did you 
give me"? Record the time of response. 

No. 3. 

Put on the table, screened from S, the 5 cubes of the same size, 
mixed in with the 3 pyramids and the 2 parallelepipeds. Show S 
another cube (the one of the series of 12 which is nearest in size 
to the 5 on the table), saying: "Do you see this bit of wood? 
Well, pick out all the bits here on this table that look like it." Re- 
move the screen, and time aS's performance. 

No. 4. 

Show the test-card of forms and the small black cube, saying: 
"Look at this bit of wood; is there anything on this card that 
looks like it"? If S answers correctly, direct him: "Pick out all 
the things that look like it." (Or: "Pick out all the squares on 
the card.") S may mark the squares with a pencil, or, preferably, 
indicate them with a small pointer. Record the time and the 
number of errors. 



472 DEVELOPMENTAL DIAGNOSIS 

No. 5. 

Put, on the table, at dilTcrent distances from H, the series of 12 
cubes of varying sizes. >S is told: " Here are a lot of bits of wood 
that look like the things you were just picking out on the card. 
Look at them carefully, and tell me how many there are, which 
is the biggest, and which is fartlu^st away from you."* Take the 
time: record errors. 

No. 6. 

With all the t(>st-niaterial concealed from view, ask *S these 
four questions, but allow time to answer each one before the next 
is asked. 

(a) "Are big things heavier or lighter than small things"? 

(6) "How does it happen that small things are sometimes 
heavier than big things"? 

(c) "Which looks bigger, a thing that is close by, or a thing 
that is far away"? 

(d) "When things are far away, do they just look smaller or 
are they really smaller"? 

Measure the times of response, and record the answers verbatim. 
In the 3d and 4th questions, E may assist young children with no 
training by illustrating with the objects selected by them (in 
No. 5) as the largest and the most distant. 

Interpretation of Data. — De Sanctis determines the grade 
of development of children as follows; (a) Ability to pass onl}^ 
Nos. 1 and 2 indicates intellectual defect of a high degree. (6) 
Ability to pass Nos. 1 to 4 only, or No. 5 with difficulty and with 
many errors, indicates a moderate degree of defect, (c) Ability to 
pass No. 5, but not No. 6, indicates but a slight degree of "mental 
insufficiency." ((/) Ability to pass all 6 tests in normal time 
indicates normal intelligence.- A child maj'' pass all 6 tests and 

' This test is not carefully described. Apparently, de Sanctis uses a dis- 
tance not over 2 cm. between the farthest and the nearest cube, and asks 
the tliree questions together, in a single sentence, as printed. Goddard 
.ari-Miipios tlie cubes so that all shall be within easy reach of the child, but that 
one shall be distinctly farther than the rest. Goddard also, apparently, 
makes thnn- se|);vrale ciuestions of those that de Sanctis joins together. The 
dilliculty of the test will evidently be considerably affected by these changes 
in arrangements of the material, and in the form of procedure. 

' No results have l)een published to show what times are to be considered 
normal. E must work these out by trial with a group of normal children. 



TEST 52: DK Sanctis' oraded series 473 

yet l)c rated as 'backward' pcdagosically; such a child may exlubit 
an abnormal character (flighty, undisciphned, incorrigible, etc.), 
l)ut he is not 'batikwaill' in the stri(;t medico-psycliological sense 
of the term. 

Results. — No statistical results have been published. De 
Sanctis and Decroly and Degand report that the tests give excel- 
lent results when applied to children from 7 to 16 years of age, 
and that these results accord closely with those of clinical exam- 
inations and with the pedagogical 'histories' of the children. 

Notes.— De Sanctis believes that by these tests one discovers 
directly (a) capacity of adaptation to situations, (6) memory for 
color, (c) capacity to recognize forms, and particularly to recognize 
the relation between a plane and a solid figure, (d) capacity to 
give persistent attention, (e) ability to enumerate objects and to 
judge their number, size, and distance, (/) ability to reason out 
relations between objects and their qualities, when they are not 
present to the senses, and (g) quickness of mental processes, 
particularly of perception, action, and thinking. 

A certain amount of disturbance is undoubtedly introduced in 
the attempt to infer mental condition when the tests are applied 
to children of different agc^s, but this difficulty ought to disappear 
after E has had due experience in administering the tests. 

Goddard thinks, too, that the effect of training is apparently 
not entirely eliminated: a child with rather good training may 
pass No. 6, and still be feeble-minded. However, if all the tests 
are passed with normal rapidity, the child may probably go back 
eventually into the regular school grades. 

REFERENCES 

(1) S. de Sanctis, Types ct degr^s d'insuffisance mentale, in A. P., 12: 
190.5 (190G), 70-83. 

(2) II. H. Goddard, The grading of backward children, in The Training 
School, November, 1908. Also issued as a reprint from the New Jersey 
Training School, Department of Psychological Research, August, 1909. 

TEST 53 

Binet-Simon graded tests : 1905 series. — The object of this 
series is to provide a quick means for the psychological diag- 



474 DEVKLOPMKNTAT. DIAGNOSIS 

nosis of the {^rado of intelligence of a backward or abnormal child 
by means of 80 tests of a simple, but precise character, suffi- 
ciently varied in type; to explore all the important phases of intel- 
lectual capacity (with special refercuice to judgment — good sense, 
initiative, adaptability), and of such a kind as to permit an intel- 
ligent investigator to form an indep(!ndent estimate of the child's 
mental equipment. The tests are designed to measure native 
ability rather than erudition or scholastic attainment. They are 
to bo administered individually, with suitable precautions to 
insure the goodwill and active cooperation of the child, and 
to avoid restraint or timidity. The tests are first applied to 
selected normal children of from 3 to 11 years of age and the in- 
sufliciency or retardation of abnormal or backward children is 
latcn- estimated by comi)arison of their results with those of the 
normal children. 

Materials. — For No. 1 : matches. 

For Nos. 2-5: a small piece of milk chocolate, a small piece 
of white wood of similar dimensions, and a piece of paper in which 
tile chocolate may be wrai)ped. 

For No. 7: three familiar objects, e.g., a piece of string, a cup, 
a key. 

For Nos. 8 and 9: a set of 8 colored pictures, representing 
familiar scenes. [These lithographs are reproductions of illustra- 
tions in the "Jingleman Jack" book, and have been selected by 
Goddard as being specially adapted for the testing of defective 
children.] 

For Nos. 10 and 13: two sheets of heavy white paper, each 
15 X 20 cm; on one sheet two straight black lines, about 0.5 mm. 
wide, one 40, one 30 mm. long, drawn end on end, 5 mm. apart; on 
the other, two lines, each 40 mm. long, similarly placed. 

For Nos. 12, 22, and 23: five cubical boxes, about 23 mm, in size 
and all of the same color, but loaded with shot so that they weigh 
3, 0, 9, 12 and 15 grams, respectively. They are marked incon- 
spicuously, so that their weights are not known to S. 

For No. 17: two sets each consisting of 12 pictur(>s* of familiar 
()bje(;ts, mounted on a single siieet of cardboard. 

' Binct iiiul Simon iisi-d i;{ ijiclurcs, Dccroly imd Dcgaiul three trioiips of 
S pici iii'es each. 



TEST 53: lUNKT-SIMON 1905 SKHIKS 475 

For No. 18: a card on which is printed the two designs shown in 
Fig. 59. 

For No. 21: five sheets of heavy paper or cardboard, each 15 X 
20 cm. In the exact middle of each one are drawn in black ink 
two straight lines, 5 mm. apart, end on end; the one line is 30 mm., 
the other is 31, 32, 33, 34 and 35 mm. on each one of the five 
sheets respectively. Three sheets, each 20 X 30 cm. on which are 
drawn similarly a standard line 100 mm. and comparison lines 
of 101, 102, and 103 mm. respectively.* 

For No. 29: two sheets of plain paper (say 20 X 20 cm.), scissors, 
pencil. 

General Purpose, Method, and Interpretation of the 30 

Tests.2 

No. t. Vifiual coordinalion. 

Move a lighted match slowly before >S"s eyes. Note whether he 
follows the mov(;rncnt with propc^rly coordinated movements of the 
head and eyes. (As an accessory test, E may ring n \)c\\ b(;hirid >S' 
to see whether he adopts a listening attitude.) 

No. 2. Prehension -provoked laduaUy. 

Place the small wooden cube in contact with the palm or back 
of aS"s hand to see whether he can execute properly coordinated 
movements of grasping. See whether he can carry the object to 
his mouth.' Verbal directions may be used, e.(j., "Here is some- 
thing for you: take it," etc. 



' Binct and Simon UHcd 15 whcotH for the former and 12 for Uie latter: it ia 
fjuite as Rimple to u.so a Hingle sheet and reverse the place of the longer line 
without H'h knowiedKC. It is not clear in what manner the originators 
conducted tliis test. 

^ The order of presentation need not follow that here given; thus, No. 6 
should really come first; No. 13 is divided between several other tests; the 
simpler ones may often be omitted; others may be shifted at convenience. 
The order here given corresponds with that assigned by liinet and Himon, 
and represents approximately the progressive difficulty of the tests. 

' In our opinion, it wouhl be better to avoid this reference to the mouth, 
since No. 4 hinges upon (S"s avoidance of this movement, and it is perfectly 
easy to test the execution of \\m- fnovement in the ff)f)d tr"-t. 



476 DEVELOPMENTAL DIAGNOSIS 

No. 3. Prehension provoked visually. 

Repeat No. 2, with the object placed within S's reach, but not 
in actual contact with his skin. This test may be combined with 
the next. 

No. 4.. Cognizance of food. 

Show *S successively the small bit of chocolate'- and the piece 
of wood of similar dimensions. See which object he takes and tries 
to eat. If S turns away, refuses to try or makes defensive gestures, 
this usually indicates a very low degree of intelligence, unless his 
conduct is due to excessive timidity or excitement. 

No. 5. Seeking food when a slight difficulty is interposed. 

This test is designed to show the presence ot rudimentary mem- 
ory, volitional effort, and ability to execute simple coordinated finger 
movements. When sure that S knows the chocolate and desires it 
to eat, wrap up a small bit of it in a piece of paper; let S see this 
done, then give him the packet and note his action. Does he, for 
instance, throw it away, eat it whole, bite off the paper, pass it 
to someone else to unwrap, make a single futile trial, succeed 
quickly, or what? 

No. 6. Execution of simple orders and imitation of gestures. 

When ;S first enters the room, E should greet him with somewhat 
exaggerated politeness, extend the hand and say " Good-morning, " 
to see whether S understands the gesture and responds to it readily. 
Ask aS to be seated : drop something and ask S (by gestures as much 
as by words) to pick it up and hand it to you: try such simple 
commands as "stand up," "close the door," "come here," etc. 
For further tests, get aS's attention, then ask him to "Do as I do." 
Try clapping the hands, putting the hands on the shoulders, be- 
hind the back, rising on the toes, etc. This test should be conducted 
merrily, like a children's game. A single characteristic piece of 
imitation is enough. Some children fail to respond merely on 
account of timidity or bad humor. 

1 It may be necessary for some children to use a more familiar food, e.g., 
a piece of cookie, candy, etc. 



TEST 53: BINET-SIMON 1905 SERIES 477 

No. 7. Cognizing real objects hy name. 

(a) Test aS's ability to touch the parts of his body that you 
name. Try easy requests, such as "Where is your hair?" (eyes, 
nose, ear, etc.) If these are successful, try a few harder questions 
(such as heart, eye-brow, elbow, etc.). It may be found necessary 
to give S a few illustrative answers to make him understand what 
is wanted. 

(6) Have the cup, key and piece of string on a table. Lead »S 
to the table, get his attention upon the objects, and say: "Give 
me the cup," etc. The results may be deemed satisfactory if S 
succeeds in designating the required objects correctly, even if he 
is somewhat awkward in his manner of doing it. Some defectives 
will designate an object, but not the right one: others may desig- 
nate the right object, but will acquiesce if E points to another 
and says: "Isn't this it?" 

(c) As a first test of suggestibility (see No. 13), ask S: "Give 
me the button." Note carefully his response. Does he pick out one 
of the three objects; does he hesitate and hunt about the table; 
does he become confused, or does he promptly say: "There isn't 
any button"? 

No. 8. Cognizing objects in a picture by name. 

(a) Show S the colored picture of The Gardeners. Ask him to 
point out various objects, e.g., "Where is the ladder? Where is 
the rake "? Try similarly the picture of the Butcher's Shop, asking 
"Where is the dog"? "Where is the knife"? etc. Note all errors, 
but do not correct S. Defective children often work zealously at 
this test; they may, for instance, point out objects before the ques- 
tion is finished, and they seem, in general, unable to adopt a 
critical or cautious attitude. Imbeciles, it is to be noted, will 
rarely confess ignorance, will rarely say : " I don't know." 

(6) For the second part of No. 13, try >S's suggestibility by 
asking: (1) "Where is the patapoumf" and (2) "Where is the 
nitchevo"1 Note aS's attitude and response carefully to see whether 
he displays any 'resistance' to the suggestion. 



478 DEVELOPMENTAL DIAGNOSIS 

No. 9. Naming objects designated in a -picture. 

Use the colored pictures of the Barber and of the Teamster, 
and proceed by a method the inverse of that in Test 8, i.e., point 
to different objects, and say: "What is that"? or ask "What is 
the man doing"? etc. Use the same questions for all ^'s and record 
the answers to each question. 

This test is sometimes much more difficult than the 8th, because 
of the childish vocabulary, faulty pronunciation, or reluctance to 
talk that some »S's display. Tests 7, 8, and 9 represent the same 
intellectual level — a level which constitutes the approximate 
boundary between idiocy and imbecility. 

No. 10. Com'parison of supraliminally different lines. 

The purpose here is not to test the fineness of S's discrimination 
of line-lengths (as in No. 21), but to see whether S understands 
how to make any comparison whatsoever. 

(a) Show *S the sheet containing the 30 and the 40 mm. lines, 
and ask him which line is the longer. Try several times, in chance 
order, with the longer line now on the right, now on the left, until 
sure whether S can designate the longer line or not. Defectives 
are apt to answer fairly promptly, but repeated trials may show 
that they are not really comparing the lines. 

(6) For the third part of No. 13, now substitute, without aS's 
knowledge, the sheet on which both lines are 40 mm. long, and 
ask as usual : " Which line is longer now? " Give this "line-trap " 
test three times. 

No. 11. Auditory memory for three digits. 

Secure the best attention that S can give. Direct him: "Say 
this after me." Give such series as 3, 0, 8 or 5, 9, 7. Pronounce 
the digits distinctly, without rhythm, at the rate of 2 per sec. 
Record aS's responses. Many /S's fail to understand the instruc- 
tions; it will then be necessary to illustrate once or twice. The 
outcome is considered satisfactory if /S succeeds on the second 
trial. E should note particularly cases in which more than 3 



TEST 53: UINET-SIMON 1905 SERIKS 479 

digits are given by S, or in which digits are recited in their natural 
order, e.g., 3, 4, 5 for 3, 0, 8, since these responses are usually 
indicative of defective mentality. In practise, this test is combined 
with No. 19. 

No. 12. Comparison of supratiminaUy different weights. 

This test has a similar purpose to that of No. 10. The essential 
question is : does S know how to go about the task of comparing 
two weights? 

Place before S, a))out 5 cm. apart, the cubical boxes that weigh 
3 and 12 g., and say: "Here are two little boxes: which do you 
think is heavier?" Try similarly the pairs 6 and 15 g., and 3 
and 15 g. Note carefully the procedure adopted by S: does he 
make a true comparison; does he lift both boxes in the same hand, 
or does he pass judgment without touching the weights at all? 
If the procedure is wrong, E should try to explain to him how the 
weights should be lifted (according to Binet, one in each hand 
simultaneously). Note whether he succeeds after this instruction. 

No. 13. SuggcdibiiUy. 

The directions for testing suggestibility are given in the three 
catch-tests already described, viz., the "button trap" (No. 7c), 
the "word traps" (No. 8b) and the "line trap" (No. 10b). S's 
that fall into all three 'traps' are extremely suggestible: those that 
resist all three have no suggestibility^: intermediate degrees are 
indicated by the amount of resistance to the several suggpstions. 

No. 14- Definition.'^ of familiar objects. 

The purpose here is to ascertain S's ability to i)ut a very simple 
idea into words, by asking him to define the words: — house, fork, 
mamma. First make sure that S knows the word, then ask him 
to define it; thus, "You know what a fork is, don't you?" "Yes." 
"Well, what is it?" If S ' balks' at the definitions, illustrate by a 

iSofar as these tests go: for other methods of measuring sugy;estil)iHty, 
consult Chapter X., Tests 40-44. 



480 DEVELOPMENTAL DIAGNOSIS 

simple definition, e.g., of a dog as " an animal that barks." Record 
S's replies verbatim. Try all three words. Watch for absurd 
replies, especially for ''echoing" replies, as "A house — why it's 
a house." Most definitions will be given in terms of function, e.g., 
"A fork is a thing to eat with." 

No. 15. Memory for sentences. 

This test resembles No. 11, save that sentences of approximately 
15 words are substituted for the three digits. Use the following 
eight sentences in the order given.^ Speak slowly and distinctly. 
Do not repeat any sentence if S fails at the first trial. As in other 
tests, note particularly the presence of absurdities in *S's responses : 
a mere omission is but an error of memory; an absurdity is an 
error of judgment and is probably symptomatic of mental defi- 
ciency. 

(1) I get up in the morning, play all day, and go to bed at night. 

(2) The horse is drawing the wagon; the road is steep and the 
wagon is heavy. 

(3) In summer the days are fine; in winter it snows and I am 
cold. 

(4) Mabel has been naughty; she will get a scolding because 
she didn't mind her mother. 

(5) It is almost one o'clock; the house is quiet and the cat is 
sound asleep. 

(6) The apple tree casts a pleasant shade on the ground where 
the children are digging. 

(7) It is not necessary that you should tell everything that you 
happen to hear about. 

(8) We should be careful not to confound the critical spirit 
with the spirit of contradiction. 

No. 16. Differences between familiar objects recalled in memory. 

This test is designed to study iS's capacity to observe, to recall 
clearly, and to draw distinctions. Three pairs of objects are con- 
trasted — (a) paper and cloth, (6) a fly and a butterfly, (c) wood 

^ These sentences differ somewhat, both in content and in order, from 
the originals, on account of the impossibility of preserving in translation 
the characteristics of the French sentences. Slightly variant renderings 
will be found in Goddard. See No. 2 of the 1908 series (Test 54) for 
another set of test sentences. 



TEST 53: BINET-SIMON 1905 SERIES 481 

and glass. In each case, make sure first that S is famiUar with both 
objects, then ask him to state the difference between them. For 
example: "Do you know what paper is? . . . Do you 
know what cloth is? . . . Then tell me the difference 
between them." It is usually necessary to indulge in further 
questioning, e. g., "Why aren't they the same?" "How can you 
tell them apart?" etc. If any of these pairs is unknown, E may 
try other objects, such as a plate and a cup, milk and water, etc. 
In general, three types of responses appear: (1) some >S's cannot 
be brought to understand the idea of expressing differences; (2) 
some >S's make absurd answers, e.g., "A fly is larger than a but- 
terfly"; (3) other S's succeed in making a satisfactory distinction. 

No. 17. Memory for pictures. 

Instruct *S: "I'm going to show you some pictures, and let 
you look at them for half a minute. After that I shall ask you to 
tell me the names of all of the pictures you saw." Display the first 
card (mouse, bag, bucket, etc.) for 30 sec. If *S appears inat- 
tentive, remind him of his task: "Don't forget, look at them all," 
etc. Record the number of objects named; note the omissions, 
insertions, and other mistakes. Note also S's general manner of 
procedure — whether his attention seems keen and persistent, 
whether he pronounces the names aloud, etc. If the first trial 
fails for any reason, try the second card of objects. If time 
permits, try both groups with all S's. 

No. 18. Drawing from memory. 

Instruct *S: "I'm going to show you two drawings (Fig. 59) 
now, and let you look at them for 10 sec. After that I want you 
to draw them from memory as well as you can." Most S's need a 
little encouragement in this test. Care should be taken that they 
begin work promptly. The results may be scored, roughly, as 
exact, similar, or very unlike (Binet and Simon), or they may be 
graded on a scale of 10 for satisfactory reproduction (Decroly and 
Degand).^ 

'■ For reproductions of the drawings made in this test by defective children, 
consult Decroly and Degand, p. 111. 



482 



DEVELOPMENTAL DIAGNOSIS 



No. 19. Auditory memory for more than three digits.^ 

Follow the directions for No. 11, but use test-numbers like the 
following: 5328, 41053, 708219, 2690325, 85023908. In each case, 
the digits are to be pronounced successively, as: five, three, two, 
eight, etc. Give three trials for each kind of number: 4-place, 
5-place, etc., until a number is reached of such a length that S is 
successful in no one of three trials. Let S state after each repeti- 
tion whether he thinks it is correct or not. 



n 



a. 




FIG. 59. DESIGNS FOR BINET-SIMON TEST NO. 18, 1905 SERIES. 

No. 20. Resemblances hetween familiar objects recalled in memory. 

This test is similar to No. 16, but here S is asked for points of 
Ukeness instead of points of difference. The same general precau- 
tions are to be taken. It will often be necessary to explain that 
two different objects may have some points of resemblance. The 
three groups of objects employed by Goddard are: (a) milk and 
snow, (6) a mosquito and a bee, (c) a table, a chair and a door. 

, • No. 21. Discrimination of lines. 

The procedure resembles that of No. 10, but the line-lengths are 
now only liminally different. 

Show S the test-cards with the longer line now on the right, now 
on the left, until he has had four trials with each card. Use first 
the cards with the 30 mm. standard, then those with the 100 mm. 
standard. Let *S judge in each trial whether the right-hand line 
is longer or shorter. The discrimination is difficult even for a 
normal adult S. 



Compare Test 38 and the results there given for normal children. 



TEST 53: BINET-SIMON 1905 SERIES 483 

No. 22. Arrangement of Jive weights. 

Place on the table the cubical boxes weighing 3, 6, 9, 12, and 
15 g. Say to S: "Here are five little boxes; they look ahke, but 
they don't weigh .the same. I want you to arrange them in order. 
First put here [at the left] the hghtest of all, next the one that is 
just a little heavier, then the next heavier, then the next heavier, 
and here [at the right] the heaviest ot all." This explanation must 
be tried in several forms, as it is rather difficult to make intel- 
ligible to many aS's, but the explanation must not suggest that the 
weights are to be hfted. Note ;S's manner of procedure: does he 
understand the directions, does he test the weights — with one 
hand or both hands, etc.? Record the order of the weights and 
rank/Sintermsof the number of displacements, i.e., the number of 
changes requisite to bring the weights into their proper order. Mix 
up the weights and let S try a second, and a third time. Compute 
the total number of errors for the three trials. The computation 
of errors may be illustrated as follows: if the order is 3, 6, 9, 15, 12, 
there are two errors; if the order is 9, 15, 6, 3, 12, there are eight 
errors; if 3, 9, 6, 15, 12, there are four errors. 

No. 23. Detection of the missing weight. 

If S succeeds fairly well in the preceding test, let him nlose his 
eyes while E picks out the 9-gram weight. Let S then examine the 
four remaining weights, which have, meanwhile, been placed equi- 
distantly, to see whether he can, by lifting alone, tell which weight 
has been removed. Repeat the test by the removal of the 6-gram 
weight, and again by the removal of the 12-gram weight, leaving 
four weights on the table in each instance.^ 

No. 24. Rimes. 

Making rimes is employed to test extent of vocabulary, general 
'nimbleness' of mind, spontaneity, etc. E must first discover 
whether S knows what a rime is. If he does not, E should try to 

1 This procedure is preferable, for comparative purposes, to tiie removal 
of a weight by chance as practised by Binet ami Simon. 



484 DEVELOPMENTAL DIAGNOSIS 

explain b}' simple illustrations, as dog, fog, log, etc. If the explana- 
tion succeeds, try for a simple test the naming of rimes to the word 
ball — ^allowing one minute for the trial. Most >S's that understand 
the test will be able to name such common words as fall, call, all, 
small, etc. Next try the word coy, then the words din, feet, spring, 
money. '^ Record in each case the words suggested by S in one 
minute. 

No. 25. Mi.'^sing words. 

The method resembles that of the Ebbinghaus 'completion' 
method (see Test 48), but is simpler in that only the final word in 
each sentence or phrase is omitted and the test is conducted orally. 
In general, the difficulty of such a test depends almost entirely 
upon the nature of the 'gap' that is to be filled. For that reason, 
all *S's should be given the same test-sentences, spoken in the same 
manner, viz: with the voice suspended at the missing word (the 
words in parentheses are omitted). If necessary, E must urge S 
by saying: "Finish it," "What comes next?" or "What should I 
say next?" etc. 

"One day a dog was walking along with a large piece of meat in his 
(mouth). Pretty soon he came to a brook and began to cross it on a(bridge). 
As he looked into the water, he thought he saw another dog with another 
piece of (meat). I'll have that piece, too, said he, droppinghis (own). But 
his meat sank out of (sight). He saw nothing but his own shadow in the 
(water). Then he knew that he had been too (greedy). I hope next time he 
will be a wiser (dog)."'' 

No. 26. Sentence-building .^ 

Ask S to make a sentence containing the three words girl, river, 
ball.^ Since many S's do not understand the meaning of the term 
sentence, E must give illustrations with other words, and try various 
forms of explanation, e.g., "Tell me something and use all these 

1 These are the test-words employed by Goddard. 

^ This is substituted for the selection used by the French investigators. 
Other words than those indicated may, of course, be properly substituted, 
e.g., plank for bridge. 

2 For similar tests, consult Test 46, and No. 43 of Test 54. 

^ These terms are substituted for those of Binet and Simon. 



TEST 53: BINET-SIMON 1905 SEKIES 485 

words when you tell it to me,"etc. Many *S's fail entirely; others 
are able to construct sentences containing one or two of the words ; 
others make three sentences with one of the words in each. Record 
the results verbatim. 

No. B7. Replies to problem-questions. 

This important test is introduced to discover S's ability to pass 
a satisfactory judgment as to what should be done in certain situa- 
tions: it is, in short, a test of the 'problem-solving' type. The 
questions are to be propounded orally in the order given below :^ 
the replies are to be recorded verbatim, and graded in terms of the 
appropriateness and degree of ' common-sense ' that they display.- 
E must exercise patience, give S plenty of time, and avoid sug- 
gesting failure by such remarks as: "You don't know, do you?" 
The slowness born of caution or difficulty in formulation of the 
reply must not be confused with that born of ignorance. 

(1) What's the thing to do when you feel sleepy? 

(2) What's the thing to do when you feel cold? 

(3) What's the thing to do when you think you'll be late to 
school? 

(4) If you find it's raining, when you start to leave your home, 
what's the thing to do? 

(5) If you are out walking, and feel tired and haven't any money 
to pay for a ride, what's the thing to do? 

(6) What's the thing to do when you miss a train? 

(7) What's the thing to do when you break something that 
doesn't belong to you? 

(8) What's the thing to do if you find that somebody has stolen 
a book out of your desk at school? 

(9) What's the thing to do if you find out that your house is 
on fire? 

(10) What's the thing to do if the boy you are playing with 
hits you without meaning to? 

(11) What's the thing to do when you want good advice? 

(12) What happens to a person who is lazy and doesn't want 
to work? 

^ Iq practise, the French investigators seem frequently to have used only 
the first 20 questions. 

- Some experience is required, in grading the answers, to avoid either 
underestimation or overestimation of their real value. 



486 DEVELOPMENTAL DL-^GNOSIS 

(13) Why should a person save some of his money instead of 
spending it all? 

(14) What would you do if you were punished when you didn't 
deserve it? 

(15) Suppose a person is planning to do something important, 
what's the first thing for him to do? 

(16) Suppose you wanted ten cents, how would you earn it? 

(17) Suppose somebody has done something you didn't like 
and comes to say he is sorry, what's the thing for you to do? 

(18) Suppose somebody asks you what you think about a boy 
that you don't know very well, what's the thing for you to do? 

(19) What happens when two persons discuss a question with- 
out understanding the words? 

(20) Suppose a boy always contradicts you, whatever you say, 
what's the thing for you to do? 

(21) Why should you judge a person by what he does rather 
than by what he says? 

(22) Wh}^ should you forgive an injury done in anger more 
quickly than you would forgive one done without anger? 

(23) Why is it better to go on and persevere with what you 
have begun than to begin something else? 

(24) Why shouldn't you keep reminding a person of the things 
you have done for him? 

(25) If you have committed some injury that can't be made 
right again, what's the thing to do? 

As illustrations of the grading of answers, take Question 9; a 
good answer would be : " Throw water on it if you can, then send 
in a fire alarm." Less good: "Save yourself and whatever else 
you can." Absurd answer: "Put stewpans on the fire and open 
the windows to let the smoke out."^ 



No. 28. Interchange of the dock-hands. 

Here it is proposed to demand of S active attention, visual 
imagination, and simple reasoning. Let E first make sure that *S 
knows how to tell time. Imbeciles are prone to declare that they 
can, but to fail utterly on trial. If S can tell time, propound the 
following query: " Suppose it is four minutes of three, can you see 
in your mind where the large hand Avould be, and where the small 

1 For fully illustrated accounts of answers to all questions, consult Binet 
and Simon,' pp. 278-292, and Decroly and Degand, pp. 120-1. 



TEST 53: BINET-SIMON 1905 SERIES 487 

hand would be?" If the answer be affirmative, continue: "Now 
suppose the large hand takes the place where you say the small 
hand is, and the small hand takes the place of the large hand, 
then what time would it be?" Try similarly the interchange of the 
hands when at twenty minutes past six. E should be satisfied to 
receive approximate answers, viz: 11,15 and 4.30, but if these are 
given successfully, E may say: " These answers are not absolutely 
right, though very nearly so; can you tell me why they are not 
exactly right?" 

The test is difficult for most *S's; some cannot undertake it at all 
or give answers that are utterly wrong; others give answers that 
are partly right, e.g., one hand is right, or the right and left sides 
of the dial are confused; still others give the correct answers, but 
only the very capable can explain the sHght discrepancy. 

In conducting the test, S must not be allowed to look at any 
clock or watch face, or to aid himself by drawing, but must work 
the problem out mentally. 

No. 29. Drawing from a design cut in a quarto-folded paper. 

The solution ot this test exacts capacities like those demanded 
in the preceding test. 

Show S the two sheets of paper and call his attention to the 
fact that they are just alike. Leave one sheet on the table, and, 
while S watches carefully, fold the other slowly twice, i.e., first into 
halves, then into quarters. Then with the scissors cut two tri- 
angular sections out of the folded edge of the sheet (small Fig. 
1 in Fig. 60), so that, were the sheet unfolded, it would have the 
appearance indicated (small Fig. 2). Give S no opportunit}'^ to 
examine the sections that have been cut out. Put the folded 
sheet before him, saying: "You see I have cut a piece out of this 
paper. If I should open it, it wouldn't look fike that piece 
[pointing to the uncut open sheet]. I want you to draw on that 
piece what we should see if we unfolded this one." Give these 
directions carefully, no more, no less. If this test proves too diffi- 
cult, it may be tried in the simpler form used by Binet, in which 
E cuts out only the upper notch of Fig. 1 . 

In the lower part of Fig. 60 are shown the results obtained by 



488 



DEVl'^LOPMENTAL DIAGNOSIS 




KiS, 1. 



FiS 2. 







Ki. ()0. OHKilNAL.S AM) KKI'IiODVCTlONS OV UINKT-SIMON TEST NO. 

(From DiHToly and Doo;an(l.) 



TE8T 53: BINET-SIMON 1905 SERIES 

Decroly and Degaiid from different S's. The numbers refer to 
the numbers of the different S's, but do not correspond with the 
numbering indicated for the same S's in Table 99, below. 

No. 30. Distinction between ahstract terma. 

Without preamble, ask S: "What is the difference between 
liking a person and respecting him"? And again, "What differ- 
ence is there between being vexed and being bored"? 

Results and Conclusions. — (1) In general, *S's fall into four 
groups with regard to each test; first, those who fail completely; 
secondly, those who succeed partially; thirdly, those who succeed 
completely; fourthly, those whose mistakes are of the absurd or 
ridiculous kind: these last are significant for the diagnosis of 
mental deficiency, and usually indicate something else than sim- 
ple ignorance or simple inability due to immaturity. 

(2) The chief obstacles encountered in the examination of defec- 
tives are ignorance of what is wanted, resistance springing from 
a morose or peevish disposition, timidity, and inability to resist 
distraction and give continuous attention to the work. 

(3) Binet and Simon have established the following standards 
for norrnal children for the ages 3 >o 12. 

(a) Nos. 1-7 are passed by all children 3 years old and upward. 

(6) Nos. 8-12 and No. 14 are passed successfully by children 7 
years old and upward : 5-year old children need some help in Nos. 
9 and 12: 3-year old children make some errors in Nos. 8 and 9, 
and succeed but rarely in No. 11.^ The characteristic mark of the 
3-year old is therefore the ability to name familiar objects in pic- 
tures, of the o-year old to repeat three numbers, to compare two 
lines or two weights (after instruction) , and to define a well-known 
object. 

(c) Suggestibility (No. 13) is extreme in the 3-year child, and 
decreases progressively in later years: the " button-trap" is avoided 
!)y most 5-year olds. 

(d) The average 7-year old child repeats 3 of the 8 senten(;es and 
makes 3 mistakes ("absurdities"), recalls 4.3 of the 13 pictures 

1 In the author's opinion, this conclusion is dubious, as many 3-year old 
children of his acquaintance can repeat three digits correctly. 



DEVELOPMENTAL DIAGNOSIS 

and can repeat 5.8 digits. In No. 21, he makes 1.5 errors. In 
No. 22, he has a misplacement of the wei2;hts of 11.3. He makes 
an indefinitely large number of mistakes in No. 23. He cannot 
make rimes, and fails to pass Nos. 20, 28, 29 and 30. In No. 27, 
(first 20 questions) he is sil(>nt from G to 11 times, and makes 
one or two absurd replies. 

(e) The average 9-year old child I'cpeats 4 of the 8 sentences, 
recalls 6.2 of the 13 jMctures and can repeat 6 digits. In tiie 
discrimination of 30 mm. lines lie makes 1 mistake. He has an 
averag(> misphicement of 4 in No. 22, and makes from 2 to 5 errors 
in the missing-w(>ight test (No. 23). He can make from 1 to 4 
rimes, Imt api)arently does no Ix^tter tlian tli(> 7->'enr old child in 
Nos. 26-30. 

(/) The average 11 -year old ehild rejieats 5 sentences with 0.5 
error, recalls 7.2 pictures, and can repeat 6 digits. In discriminat- 
ing 30 mm. lines, he makes 0.2 errors. His misplacement of 
weights is 2.4, and his errors in the missing-weight test are 2. He 
may succeed veiy crudely in drawing from the cutting. He makes 
several iim(>s, does fairly well with No. 27 (mininunn, 2 "silences'" 
and 0.5 "absurdity," maximum 5 "sil(Mices"aud 2 " absurditi(>s"), 
but does scarcely anything with Nos. 20, 28, 29 and 30. 

(4) S>'st(>matic application of these t(>sts to defective childrcMi 
by Decroly and D(>gand has yielded the results which are sununar- 
ized in Table 99.' In the light of (he explanation which folloAvs 
the Table, it will be seen: 

{a) that there is a very good general cori'es|)ondence between 
the classification of these defectives on the basis of ])edagogical, 
clinical, and general observation and their classification on the 
basis of the tests, so that the t(^sts ha\'e a i)ractical \'ahi(> for the 
psychological classification of defiH-tives; 

(/>) that they are not well adaptedfor th(> diagnosis of deat-nuites 
(or, it may be added, of moral defectives) -^ 

' Kxpcriiucntcis wlio wisli (o apply (Ik-sc Icsl.s (o defectives are reeoin- 
niended to consult the detailed residls Iroiii which this .sunnuary has been 
made, as well as the results of liinet and Simon with abnormal childreii. 

' J3ecroly and Def^and sugf!;es( as im])rovements for the liinet-Simon series, 
the addition of tests ada])te(l for deaf-nnites and moral defectives, the ad- 
dition of tests l)earing more particularly ui)on what they term "active 
intelligence, alertness, or logic in action" to till out the evident inadecpiacy 
in this i-espect of \os. IS and 22, and the r(>arrangement of certain tests 
that al present are unnecessarily long, or that entail needless repetition. 



TEST 53: BINET-SIMON 1905 SEKIE! 



491 



TABLE 99 

.1 Pl,lirali<»i of the 1905 Bincl-Simon Tests to Defectives (Deeroly and 
D eg and) 



No.of 


Number of Test 


H.il.i 


() 7 S 9 10 


11 12 13 14 15 


Ki 17 IS 19 


20 21 22 23 24 25 


26 27 28 29 30 


1 


YY 








2 


YYYS 












3 


YYYY P 


P S S 


s 








4 


YYYP P 


Y P P P P 


P P P V 


P P 






5 


YYYY Y 


Y Y S S 


s s 


' S 


S 
S 




6 


YYYS Y 


V Y P S'S 


YSSS 


S S P P s s 




7 


YYYS Y 


Y S P S S 


S S 








8 


SYSS Y 


Y 


s 


s 




S 


9 


YSSS S 


Y Y S S S 


SYY S 


S S Y \ S 


s 




10 


YYYY Y 


Y Y S S S 


Y Y S S 
S Y S S 


S S S 


s s 




11 


YYYY Y 


Y Y P S S 


S S Y Y S S 


s 




12 


S Y 




Y 






s 


13 


YYYS Y 


Y Y S Y S 


SYSS 


S P Y Y Y Y 


P s s 


S P 


14 


YYY S Y 


Y Y S Y Y 


Y Y S \ 


S Y Y Y Y Y 


S Y P 


S P 


15 


YYYS Y 


Y Y P S Y 


s s s s 


S Y 


s 
P s s 


s 


16 


YYY S Y 


Y H Y Y^ S 


Y S S Y 


S ! S S S Y S 


S P 


17 


YYYY Y 


Y S S Y Y 


YYYS 


Y S S S Y Y 


P S Y 


S P 


18 


SY Y 




s 


s 




s 


19 


SYY Y 


Y S S 


YYY 




s 


20 


YYYY Y 

SYYS Y 


Y Y S Y S 

s s 


Y Y Y S 


s! S Y Y Y Y 


s 


Y P 


21 


S 


1 Y Y Y 




Y 


22 


YYYY Y 


Y Y S Y S 


Y Y S S 


S ■ Y Y Y S S 


s s 


Y 


23 


YYYY Y 


Y Y Y Y Y 


YYYYYYYYYY 


S Y 


s s 


24 


YYYY Y 


YYY S Y 


Y S Y Y 


S S S Y Y S 


S Y 


Y P 


25 


YYYY Y 


Y Y SYY 


YYYY 


S Y S Y Y Y 


Y S S 


s s 



PJx'planation of the table. The symbol Y (Yes) indicates complete success; 
I lu! symbol S (Some) indicates partial success; the symbol P (Poor) indicates 
poor results; omission of a symbol indicates no response at all. It must be 
understood that many of the omissions in this table are cases in which the 
tests could not be applied; thus, Nos. 8, 12, and 21 are deaf children, while 
Xos. 18 and 19 arc partially deaf. The first 5 tests are passed by all. 

The children are numbered in order of theirgeneral intellectual capacity : 
Nos. 1 and 2 exhibit extreme defect, and are classed as idiots with imita- 
tion of gestures; Nos. 3 to 7 exhibit marked defect, and are classed as im- 
beciles; Nos. 8 to 13 are feeble-minded children with moderate defect; Nos. 
14 to 17 suffer only mild deficiency and may be ranked as backward children; 
Nos. 18 to 25 possess normal intellectual capacity in general, but need, 
with the exception of No. 25, a certain amount of assistance in order to suc- 
ceed outside of an institution. 



492 DEVELOPMENTAL DL^GNOSIS 

(c) that the tests are not so serviceable for the diagnosis of chil- 
dren whose capacity lies between the normal and the abnormal; 

(d) that the tests are not arranged at present in precisely the 
order of their difficulty, at least for defective children, e.g., No. 
9 is evidently more difficult than No. 10; or, in other words, that 
failure to pass a given test does not necessarily involve failure 
to pass all su])scquent tests, e.g., Child No. 13. 

(5) Binet and Simon advance the following classification of 
defectives on the basis of their tests: the figures in parentheses 
in(li(!ate the number of the limiting test. 

A. Idiots (no use of language). 
A 1. Vegetative idiot with no relational activity (0). 
A 2. Idiot with visual coordination (1). 
A 3. Idiot with prehension (2, 3). 
A 4. Idiot with knowledge of food (4). 
A 5. Idiot with capacity to imitate (G). 

B. Imbeciles (roughly equal to the 2-5 year normal child). 
B 1. Imbecile with capacity to name (7, 8, 9). 
I^ 2. Imbecile with capacity to compare (10, 11, 12). 
B 3. Imbecile with capacity to repeat sentences (15). 

C. Feeble-minded. 
C 1. Feeble-minded with capacity to state differences (16). 
C 2. Feeble-minded with capacity to make serial arrange- 
ments (22). 

REFEREiNCEH 

(1) A. Binet and T. Simon, (a) Sur la nocessitc d'6tablir un diagnostic 
soiontifique des 6tats inferieurs de I'intelligence, in A. P., 11:1905, 163-190. 
{b) Mothodes nouvelles pour le diagnostic du niveau intellectuel des anor- 
maux, ibid., 191-244. (c) Application des mothodes nouvelles au diagnostic 
du niveau intellectuel chez des enfants normaux et anormaux d'hospice 
et d'ccole primaire, ibid., 24.5-336. 

(2) O. Decroly and (Mile) J. Degand, Les tests do Binet et Simon pour 
la mesure de I'intelligence: contribution critique, in Ar. P., 6: 1906, 27-130. 

(3) H. H. Goddard, The Binet and Simon tests of intellectual capacity, 
in The Training School, 5: December, 1908, 3-9. (Also reprinted as "The 
grading of backward children,' New Jersey Training School, Dept. of p.sycho- 
logical research, August, 1909.) 



TEST 54: BINET-SIMON 1908 SERIES 493 

TEST 54 

Binet-Simon graded tests: 1908 series. — The following tests, 
like the preceding group b\' the same authors, form a graded series 
for the quantitative determination of native ability and general 
intelligence. Many of them are repetitions, with slight modifica- 
tions, of the preceding tests, but there are 33 new tests, so that 
the series as a whole is more extensive, and may be assumed to 
represent a more satisfactory^ combination for the purpose, not 
only of diagnosing the degree of retardation of backward children, 
but also of estimating the degree of development of normal chil- 
dren from 3 to 13 years of age.^ 

The tests have been classified by the ages to which they apply in 
normal children. An effort has been made to eliminate the varia- 
ble error due to training, by giving preference to tests which measure 
native ability or natural acquisition rather than erudition or the 
capacities developed by school training. 

As before, the tests are to be administered individually, \vith 
suitable precaution to avoid timidity or obstinacy on the part of 
the subjects. E should encourage S by the adoption of a friendly 
and kindly tone of voice, but should not give him direct assistance 
or instruction in explanation of the tests (save where noted), 
and should never venture to criticize. He must be tactful, patient, 
and sympathetic. It is well to have a third person present to act 
as clerk for recording >S's answers, but no spectators should be 
alloAved. 



1 As it is not clear whether Binet and Simon regard this as a complete 
substitute for their earlier series, the tests have been reproduced entire, 
following the divisions of the authors into groups which are intended to re- 
present norms of average capacity for the several ages mentioned. These 
performances are those of more than 200 French school children, drawn in 
large degree from the poorer classes. It is to be desired that norms may soon 
be established for American children with the same series of tests, especi- 
ally since the recent investigation by Decroly and Degand of normal children 
in the Brussels schools makes it evident that not a few of the Binet-Simon 
age-norms must be revised. 

Experimenters will doubtless find it profitable to select some tests from 
the 1908, and some from the 1905 series, because, as Decroly and Degand 
point out, several of the tests now omitted were of special interest. 



•494 DEVIOLOI'MIONTAL DIACNOSIS 

A. TESTa FOli 3-VEAK OLD ClllLDKEN 

No. 1. Comprehension of lamjuage. 
This is identical with No. 7 a of the 1st scries. 
No. 2. Memory for senteuees. 

Tliis test is like No. 15 of the 1st series, save tliat the sentences 
are arranovd iuaprof>,ressiveseriesof 2, 4, .... 42 syllables.^ 

The sentences ar(> to be tested in tiie order given (though the 
shorter ones may be omitted for older children). Each sentence 
is read aloud to »S slowly and distinctly, and he is asked to repeat 
what he has just heard. 

The average 3-year old can repeat a combination of 6 syllables 
(No. 8), but not one of 10 syllables (No. 5). 

(1) Papa. 

(2) Slipper. Letter. 

(3) It is cold and snowing. 

(4) I have a dog. He's a fine one. 

(5) His name is Jack. Oh, what a naughty boy! 

(6) It is raining outdoors, but we can stay inside. 

(7) We are having a fine time. We found a mouse in the trap. 

(8) Let's all go for a walk to-day. Please give me that big hat 
to wear. 

(9) Poor Helen has just^ torn her new dress. She will surely 
feel sorry for that. 

(10) Why should any one want tt) do injury to such beautiful 
creatm-es as birds? 

(11) We expect to have a great time at the seashore, digging 
in the white beach sand all day long. 

(12) When the train crosses the road the engineer will blow the 
whistle and the fireman will ring the bell. 

(13) My 3njung brother Frank had a line time on his vacation 
this sunnner: he W(Mit fishing almost every day. 

(14) To start a fire in the open is one of those tricks that every- 
one thinks he can i)erform until he tries it. 

(15) He sinks the ni't in the water and waits until he can see 
the fisli distinctly, lying perfectly still and within reach. 

' Tlie sliorter sentences are largely adaptations of the series used by Binet 
and Simon, and the general type anA suliject-matter of the original sentences 
has lieen preserved so far as possilile. Tlic longer sentences have been ar- 
ranged by the author. Tliis test is not. of course, intended to be used in 
its entirety for 3-year old childrtMi: the longer sentences are used for older 
children, as is described below. The whole series has been collected in one 
group for convcMiioiicc in reforence. 



TEST 54: BINKT-SIMON 1908 SERIES 495 

(16) The first rapid was only the beginning: half a mile below 
we could see the river disappear between two points of rock. 

(17) One day the children's grandmother came to visit them 
and the children were very happy because she told them beautiful 
fairy stories. 

(18) Louis looked out of his window one night and saw that 
some of the older boys were l)urning big piles of dry autumn leaves 
in the street before his house. 

(19) The Indians used to perform many kinds of queer, hor- 
ril)le dances in the course of which they yelled and shrieked as if 
suffering the most painful torture. 

(20) A full-grown grizzly bear will usually weigh from five to 
seven hundred [)ounds, l)ut exceptional individuals undoubtedly 
reach more than twelve hundretl-weight. 

(21) When you set out to explore one of these minor streams 
in your canoe, you have no intention of epoch-making discoveries 
or thrilling or world-famous adventures. 

No. 3. Memory for difjits. 

This is the same as Nos. 11 and 19 of the 1st series, save that S 
is tested with one, and with two, as well as with three or more 
digits. Many 3-year old children can repeat 2 digits without 
difficulty, but cannot repeat 8 digits correctly. 

No. 4. Description of a 'picture. 

This test resembles somewhat both the description test of 
Chapter VIII, and No. 9 test of the 1905 series, though it differs 
from both in some essential features. The authors regard it as 
extremely valuable, because it arouses great interest, and because 
it affords insight into the grade of »S's intelligence. 

Material. — Set of 8 colored pictures, as in Nos. 8 and 9 of the 
1905 series.^ 

' Dr. Goddard, who has employed these pictures in the examination of 
retarded children at Vineland, N. J., writes of this test: "We find it valu- 
able to use the whole set of pictures, or at least five or six of them, because 
it often happens that a child who does not at first notice the action [i.e., 
does not appreciate or name the situation that is pictured] because his at- 
tention is attracted to some special feature, may notice it in the 2d, or 3d, 
or 4th, or even sometimes not until the last picture. If we get this reaction 
at all, we feel that the child displays a higher grade of intelligence than if 
he merely names a man or a woman or some other single object. We find 
many intermediate grades that are very suggestive." 



496 DEVELOPMENTAL DIAGNOSIS 

Method. — The picture is shown to S, who is urged to describe 
it (from direct observation). E may ask: "What is that"? "What 
do you see there"? "Tell me what that is about, ' ' etc. 

Results. — At least three types of answers may be distinguished : 
(1) simple enumeration, e.g., "A man, a dog, a knife," etc., (2) 
description, (3) interpretation. The 3-year old child gives only 
replies of the first type, though the best children at this age may 
use a few connectives, e.g., "A man and a dog," etc. 

No. 5. Family name. 

Ask S: "What is your name"? If only the Christian name is 
given, try to ascertain whether the child also knows his family 
name. Man}^ 3-year old children fail to pass this test. 

n. TESTS FOR 4-YEAR OLD CHILDREN 

No. 6. Own sex. 

Ask S: "Are you a little boy or a little girl"? Many 3-year old 
children answer erroneously, but the normal 4-year old child does 
not. 

No. 7. Navving familiar objects. 

Show *S successively (1) a key, (2) a closed penknife, (3) a penny: 
in each case ask: "What is that"? According to Binet and Simon, 
most 3-year old S's, but only a few 4-year old S's, fail. 

No. 8. Memory for three digits. 

This is the same as No. 3. Four-year children can repeat 3 
digits. 

No. 9. Comparison of two lines. 

This test is closely similar to No. 10 of the 1st series, save that 
the authors employ slightly longer lines, viz: a 5 cm. and a 6 cm. 
line, drawn parallel to one another at 3 cm. distance. 

Normal 4-year old *S's should be able to indicate the longer line 
without hesitation. 



TEST 54: BINET-SIMON 1908 SERIES 



497 



C. TESTS FOR 5-YEAR OLD CHILDREN 

No. 10. Comparison of swpraliminally different weights. 

This test is identical with No. 12 of the 1st series. The actual 
weighing is, of course, not the difficult feature: the question is: 
does >S know how to make a comparison of two weights? The test 
can, as a rule, be passed at 5 years, but not at 4. 

No. 11. Copying a .square. 

Draw Avith ink a square about 4 cm. on a side, and ask S to 
reproduce this square. He must use pen and ink (or fountain- 
pen), but not a pencil. It will be found that most children reduce 

□ □ a 






FIG. 61. COPIES OF THE SQUARE. 

(No. 11, 1908 Binet-Simon series.) 

the size of the square, but their drawing is to be graded entirely 
in terms of its qualitative excellence. The first three drawings in 
Fig. 61 arc ranked as successful, the last three as unsuccessful 
attempts at reproduction. 

No. 12. The divided rectangle. 

Provide two bits of cardboard, each 8 X 14 cm. Cut one card 
along its diagonal. Place upon a table the uncut card and the two 



I'.>S DlOVIOLOl'MKNTAl. l)IA(iN()SIS 

lijilvcs of (lie (iiii (•jird, so disposed lliai their hypol.euuscs ;ire not 
ill juxtaposiiioii. Ask N; "Put thes(^ two pit^ces togetlicr to make 
a, li}>;ure lilv(> iliat one" 1 pointing to the roctanj2;le]. If aS balks at 
th(^ tost, lio must Ix' encouraged to try: if hv. happens to turn one 
pie(!(! over, he must be started again: if he asks questions as to 
1 h(> cornnitness ol his solution, E should not venture assistance. 

Not more than one in 3 of 4-3a'ar old >S's succeed, but not more 
tlwui one in 12 ol" r)-y(>ar old N's fail. 

;V(>. /.'■). (■(H(nlin(i four pomies. 

i'lace on I h(> table four peimies, close together, all in full view. 
Sav to N.' "How iWAwy peimies are there? Count them." Insist 
upon distinct counting —"one, two, three, four." 

No .S-yc^ar old >S"s succeed; about half of the 4-year olds succeed, 
but at 5 y(>ars, only backward children fail. 

I). I'KS'rS l'()K ()-VKAH OLD OHILDIIKN 

Mo. I /. Kiioirinij riijlit and left. 

Ask S: "Show me _\'our rigid hand," and, after this is done, 
"Show me your left (>ar." lie earelul lo give no hint by word or 
l(»ok. The test is jjassed even if tlu^ responses are made hesitatingly. 
Practically every 4-year old child will point to his right instead 
of (() his l(>ft ear: about one child in three of the 5-year olds makes 
an error, whereas no (-hild fails at the age of (). 

No. I'). Mciuorii for sctiknccs {1(1 .^i/llohlcs). 

Children of six yiviis should be able to re{)eat the first 9 sen- 
tences of Test No. 2. Only ont>-half of t.lios(> tcsttMl at the age of 
") i-an acc(.)mplisli (his. 

No. K). I'JIcincntorj/ cdltctic jtahjincnt. 

S is shown in succession a cartl containing the three pairs of 
drawings of u^omen's he uls shown in Fig. G2, and is asked in each 
instanc(>: "Which of these two is the prettier"? The correct 
answers are given by 6-year old children, but by only about one 
Inlf of r)-vear old chiKlivn. 









mo 02. l>UAWINfl.S h<}H TIOHTINO KLIOMKNTAHV HHTIIKTIC JIJDOMKNT. 

(No. 1(1, I'.IOS Binel-Siirion Hcrif.s.) 



500 DEVELOPMENTAL DIAGNOSIS 

No. 17. Definitions of familiar objects. 

The test is the same as No. 14 of the 1905 series, save that the 
words to be defined are (1) fork, (2) table, (3) chair, (4) horse, 
(5) mamma. Practically all children six j'-ears old succeed in giving 
simple functional definitions, i.e., definitions in terms of use; 
younger children usually define only one or two of the terms. 

N^o. 18. Execution of a triple order. 

Young children can easily execute a single simple order (see 
No. 6 of the 1905 series), but may fail if the order is complicated. 
Give S an order which really combines three separate orders in 
the one set of instructions, for example: ''Here is a key; please 
put it on that chair. Then please close the door. Then you'll 
notice a box on a chair near the door; please bring me that box. 
Do you understand? First put the key on the chair, then close 
the door, then bring the box. Now, go ahead." 

Hardly any 4-year old child executes all three orders correctly; 
of 5-year old children, about one-half succeed; of 6-year old chil- 
dren, nearly all succeed. 

No. 19. Own age. 

Ask S: "How old are you"? It is only from the 6th yeax up that 
the majority of >S's answer correctly: prior to that time, most 
children give their age too young. 

No. 20. Knowing morning and afternoon. 

Ask S: " Is it morning or afternoon"? Since a tendencyis shown 
by some children always to take the latter of two alternatives, it 
is well, if the time is afternoon, to put the question: "Is this after- 
noon or morning"? Young children, if they answer at all, answer 



TEST 54: BI NET-SIMON 1908 SERIES 501 

more or less evidently by chance, but most 6-year children answer 
correctly and without hesitation.^ 

E. TESTS FOR 7-YEAR OLD CHILDREN 

No. 21. Unfinished pictures. 

S is shown a card containing the four outline drawings of Fig. 63, 
and is asked, with respect to each drawing : ' ' What is gone (lacking) 
in that picture"? If he replies "legs," ''neck," etc., though these 
answers are, strictly speaking, correct, he is urged to say whether 
there is anything else missing. The test is passed if the correct 
answer is given in 3 of 4 cases. 

The replies of 5-year old S's are usually entirely inadequate; 
those of 6-year ,S's are correct in about one-third of the cases, but 
those of 7-year S's should be correct in three-fourths of the cases. 

No. 22. Number of fingers. 

Ask »S : " How many fingers have you on your right hand"? "On 
your left hand"? "How many does that make on both hands"? 
Pause for the reply after each question. The replies must be made 
quickly, without stopping to count, and all three, questions must 
be answered correctly to pass the test. 

This is essentially a 7-year test, since half those tested at 6 years 
fail. 

No. 23. Writing from copy. 

The phrase "See little Paul" is ^vritten in ink. *S' is to copy 
this with pen and ink. The test is passed if the copy is sufficiently 
legible to be read by a person who did not know what was to be 
written. This test is, of course, conditioned by training, but never- 
theless it forms a useful index of general intelligence. 

'■ It may be well to point out that in this, and in naany of the tests, the 
grading of average ability seems at first sight too low, but due allowance 
must be made for the fact that the child is placed under rather unusual 
conditions and that the tests are made rapidly, so that confusion may easily 
appear. 



502 



DEVELOPMENTAL DIAGNOSIS 



_-o 




FIG 63. THE UNFINISHED PICTURES. 

(No. 21, 1908 Binet-Simon series.) 



TEST 54: BINET-SIMON 1908 SERIES . 503 

No. 24- Copying a diamond. 
Repeat No. 11, but use a diamond instead of a square. 

No. 25. Memory for five digits. 
This is the same as No. 3. Seven-year S's should repeat 5 digits. 

No. 26. Description of a picture. 

This is the same as No. 4. Seven-year children should not merely 
enumerate individual features, but describe the picture as a scene. 

No. 27. Counting thirteen pennies. 

The test is identical with No. 13, save that 13 pennies are sub- 
stituted for the 4 there employed. The pennies, which are placed 
in a row, must be counted with the finger, aloud, without an error. 

No. 28. Naming four common coins. 

S is shown, successively, a penny, nickel, dime, and quarter, 
and asked to name each one.^ Passed by a majority at the age 
of 7. 

F, TESTS FOR 8- YEAR OLD CHILDREN 

No. 29. Reading and report.'^ 

Binet and Simon, as noted in the previous series, characterize 
the imbecile by inability to use printed or written language (after 
an effort has been made to teach him, of course) . The following 
test is, therefore, deemed by them important as a boundary test. 

Method. — Ask S to read aloud the following, and record his 
time in sec. 

' Binet and Simon used 0.05, 0.10, 0.50, and 5.0 franc pieces. 

^ See Chapter IX, Test 39, for more elaborate tests of 'logical' memory, 
as applied to normal children, and Chapter VIT, Test 28, for other tests of 
reading. 



r)()l DKVI'lLOl'MKN'I'AL I)IA(JN()SrS 

Three Houses Burned. 

Boston, September 5th. A serious fire last night de- 
stroyed three houses in the center of the city. Seventeen 
families are without a home. The loss exceeds fifty thou- 
sand dollars. In rescuing a child, one of the firemen 
was badly burned about the hands and arms. 

Two sec. .'iflcr the rcad'mi;' is liiiislied, remove the (cxt, aiul ask 
*S'.- "Tell me what nou have ix'cn rcadiiif"; about." Record his 
report vtM-bal.iiu. liiM-ord also the type oi his reading — whether 
(1) lett(>r-l)y-h>tt(«r, (2) by syUables. {'.]) hesitating, (4) straight- 
lorwai-d, or (f)) expressive. 

N's report is gradcMJ in terms ol' (lie luimbei' of coiislit uen( ideas 
repnxhiced, in ('omi)urison wit h t he full cpiota of 20 ideas, which is 
(\stimat('d as follows: 

Three ] hous(>s | biirn(>(l | lioston | Sept(>mber !\{\\ \ a serious 
(ire 1 last, night \ destroyed ] three buildings | in the center of the 
ci(\' I seventeen | families | are without a home | the loss exceeds | 
fifty thousand dollars | in rescuing | a child ] one of the firemen | 
was badly ] burned | about tlu^ hands and arms. 

( 'ount only coii-ect rei)orts, e.g., the report — "A house on fire. 
A lit lie boy had his hands burned"- counts only 3 credits. 

Kkshltjs.- (I) l''or the l<'r(>nch text (53 words), the following- 
average rates of leading wi're found: at 8 years, 45 sec, at years, 
10 sec., ai 10 years, 30 sec, at 11 years, 25 sec. 

(2) Th(>re is a positive reflation between rate of ri^ading and range 
of i-(>call, i.e., N's who I'cad slowly, recall fewer items. Even the 
slowest reader can r(>i)ort 2 ideas, but no S can report 6 ideas or 
more mdess he is abl(> to read the text within 1 min. 

{'A) Ability to r(>ad the text and recall at least 2 idc^as is rare at 
the age of 7, but almost invariably j)resent at the age of S. 

No. ti(K Coantimj vio)icy. 

Place ui)on a table, close toget her and in full view, two dimes and 
two nickels.' Ask N: "Count that money and tell nu' how much 

' Godcliu'it rocoinincnds tin- use of threo 1-cont, and three 2-cent stamps. 
Rinet and Simon 'iis(>d (i .so^.s, Mutc 'simples' and three 'doubles.' 



TEST 54: BINET-SIMON 1908 SERIES 505 

there is." "How much does that make"? The counting should 
not consume more than 10 sec, and the test is not passed unless 
it is completed within 15 sec. Note the manner of counting. Any 
error is termed a failure. The test can be passed by many children 
at 7 years, but by all children at 8 years. 

No. 31. Naming four color H. 

This is not a test of discrimination, but of naming. The child's 
ability to discriminate colors is nearly equal to the adult's. 

Method. — Paste upon a piece of cardboard four rectangles 
(2X6 cm.) of red, yellow, blue, and green paper. Touch each 
piece, saying: "What color is that"? The test should be com- 
pleted within 6 sec. A single error is interpreted as a failure.^ 

No. 32. Counting backwards from twenty. 

Like the preceding, this is a test that depends in part upon the 
extent and nature of school or home training. Ask *S to count from 
20 to 0, backwards: if necessary, start him by saying, "20, 19, 18, 
what comes next"? To pass this test, *S must complete the count- 
ing within 20 sec, and with not more than one error of omission or 
transposition. 

Those who fail either balk entirely, or start correctly and then 
reverse and count forwards, or succeed only by the laborious 
method of finding each number by counting up from 1, and thus 
exceed the time-limit. 

No. 33. Writing front dictation. 

Require >S to write with pen and ink, from dictation, the phrase: 
"The pretty little girls." As in No. 23, the writing must be 
sufficiently legible to be read by a person who did not know what 
was to be written. Only one-third can succeed at 7 years: all 
succeed at 8 years. 

^ The author has elsewhere (5) discussed the capacity of children to learn 
and employ color-names. Very much depends upon home and early school 
training. 



506 DEVELOPMENTAL DIAGNOSIS 

No. 34- Differences behveen familiar objects recalled in memory. 
The test is identical with No. 16 of the 1st series. It is regarded 
as of special value, because it depends less upon school training 
than do the immediately preceding tests. The test is passed only 
if 2 of the 3 distinctions are correctl}^ given within 2 min. Only one 
S in three succeeds at 6 years, nearly all succeed at 7 years, and 
all at 8 years. 

G. TESTS FOR 9- YEAR OLD CHILDREN 

No. 36. Knowing the date. 

See if *S knows: (1) the day of the week, (2) the month, (3) the 
day of the month, and (4) the year. 

Children oftenest fail to know the year. The test is passed if 
the day of the month is given within 3 days, either way, of the real 
date. Capacity to pass the test is not commonly attained before 
the 9th year.^ 

No. 36. Reciting the days of the week. 

Ask S to name the days of the week in order. This should be 
done in less than 10 sec, without error or hesitation. 

No. 37. Making change. 

This test is designed to afford insight into >S's capacity to 
perform a characteristic, every-day ' social' activity . It should be 
conducted in the form and spirit of a game, something in this way : 

Ask S to 'play store' with you. Let him be 'store-man,' sell 
you some goods, and make change for you. Give him some boxes 
or other simple objects to sell, and supply him with an open box 
(about the size of a cigar-box), which contains 13 pennies, 5 nickels, 
2 dimes, 2 quarters, 1 halt-dollar, 1 silver dollar and 1 dollar bill. 
Offer to buy a box of him for four cents, saying: " I will pay you, 
say, four cents for one of your boxes, sha'n't I"? Then hand him 

' Some of the younger school children tested by Binet and Simon had been 
given daily instruction in reciting the day, date in the month, etc., yet 
failed utterly to pass the test. This is cited as an instance of the uselessness 
of formal instruction prematurely given. 



TEST 54: BINET-SIMON 1908 SERIES 507 

a quarter in exchange for the box, and extend your hand for the 
change. 

The only 'pass' for this test is the correct counting out of the 
required 21 cents in change.^ Record the manner, speed, and 
correctness of S's counting. A few 7-year children, about one- 
third of 8-year children, and all 9-year children, pass the test. 

No. 38. Definitions of familiar objects. 

This is the same as No. 17: the child who is 9 years old is ex- 
pected, however, to give definitions that shall contain something 
more than a simple statement of the functional nature of the term, 
and classificatory definitions should be given by many children, 
e.g., "A horse is an animal to draw carriages." ''A mamma is a 
woman that takes care of her children," etc. 

No. 39. Reading and report. 

In test No. 29, above described, the 9-3'ear child should be able 
to report at least 6 items. 

No. Jf.0. Arrangement of five weights. 

This is identical with No. 22 of the 1st series. The 9-year child 
should arrange all 5 weights correctly in 2 of 3 trials, and in not 
over 3 min. per trial. 

H. TESTS FOR 10-YEAR OLD CHILDREN 

No. 4i- Reciting the months of the year. 

Ascertain whether S can name in order the months of the year. 
To pass; the series must be given within 15 sec, and with not 
more than 1 error of omission or transposition. 

1 Goddard gives the child 25 pennies, 5 nickels, and 2 dimes, and hands 
him a quarter for a 9-cent article. The child must actually give 16 cents 
in change, as well as say it. 



508 DEVELOPMENTAL DIAGNOSIS 

No. 1^.2. Naming nine pieces of money. 

Place on the table in a row, but not in regular order, a ten-dollar* 
a five-dollar, and a two-dollar bill, and six coins — dollar, half-dollar, 
quarter, dime, nickel, and cent. Let S point them out, one by one, 
and name them as he points. 

No. 43. Sentence-building. 

Follow the directions given in No. 26 oi the 1905 series, but write 
the three terms, girl, river, ball, and supply *S with pen and ink for 
the writing of his sentence, which should be finished within 1 inin. 

The responses to this test may be divided into (1) those in which 
there are virtually three distinct sentences, e.g., "1 saw a girl. 
Here is a river. Where is my ball?"; (2) those in which there 
appears a single sentence with two distinct ideas, e.g., ''The girl 
lives near a river and has a ball"; (3) those in which the three 
terms are combined into a single idea, e.g., ''The girl lost her ball 
in the river"; and (4) those in which the three terms are combined 
in a more elaborately contrived, well coordinated sentence, e.g., 
"Qne day, when T was a little girl, I was walking along the bank 
of a river, when 1 chanced to look up and spied a ball floating on 
the water." Replies of the first type are classed as failures: on this 
basis it is found that the test can be passed by a few 8-year old 
S's, by about one-third at 9, one-half at 10. The good sense, as 
well as the grammatical construction of the sentence, should be 
considered in estimating *S's intellectual capacity. 

No. 44' Replies to problem-questions. 

A test that can be passed by about one-half of 10-year old S'a 
is formed by selecting two series of questions from No. 27 of the 
1905 series, as foilows: Series 1: Questions 6, 10, 7; Series 2, Ques- 
tions 3, 15, 22, 18, 21. S should be allowed at least 20 sec, if desired, 
to formulate his answer for each question. His rank is estimated on 
the basis of the complete series of answers, and E may 'tolerate' 
2 'bad' answers in 5. As not more than half of 10-year old S's 
can answer the majority of Series 2 satisfactorily, the test forms 
a transition between the 10-year and the 11-year tests, proper. 



TEST 54: BINET-SIMON 1908 SERIES 509 

I. TESTS FOR 11-YEAR OLD CHILDREN 

No. 43. Detecting absurd or contradictory statements. 

Alienists sometimes, in the course of the examination of patients, 
endeavor to see whether the patients will assent to ridiculous 
assertions. The present test is designed for a similar purpose, but 
the inquiry is so framed as to challenge the pupil to detect and 
explain the absurdity. 

Explain to *S." " I'm going to tell you something that has a ' catch' 
in it : you listen carefully and see if you can tell me where the non- 
sense is." 

(1) "An unfortunate bicycle rider broke his head and died instantly: he 
was picked up and carried to a hospital, and they do not think that he will 
recover." 

(2) "I have three brothers, Paul, Ernest, and myself." 

(3)1 "John is taller than I am; Henry is taller than John, and I am 
taller than Henry." 

(4) "We met a man who was finely dressed: he was walking along the 
street with his hands in his pockets, and twirling his cane." 

(5) "The engineer said that the more cars he had on his train, the faster 
he could go." 

(6) "The other day I was walking to Boston when I met a fine team: 
there were two men on the front seat, and a man, a woman, and a baby on 
the back seat: so five were going to Boston." 

The test is passed if the absurdity of 3 of the first 5 statements is 
detected. Almost no child can do this at 9 years, scarcely one 
child in four at 10 years, and about one child in two at 11 years. 



No. 46. Sentence-building. 

Test No. 43, when tried by 11-year old >S's, should yield sentences 
of the 3d or 4th type. 

1 Nos. 3-6 are substituted for the rather blood-curdling series proposed by 
Binet and Simon, viz : (3) "There was found in the park today the body of 
an unfortunate young girl, frightfully mutilated, and chopped into 18 
pieces. It is thought that she committed suicide." (4) "There was an 
accident on the railroad today, but it was not serious; there were only 
48 killed." (5) "Some one said: 'If I kill myself in despair some day, I 
sha'n't choose Friday to do it, because Friday brings you bad luck.' " 



510 DEVELOPMENTAL DIAGNOSIS 

No. Jf.7. Naming words} 

Require >S to name as many words as he can in 3 min. Explain 
that any words will do, and stir him to do his best by assuring him 
that some children can name 200 words in this time. If necessary, 
start a series for him, e.g., "beard, table, skirt, carriage," etc. 
If possible, record the series given by *S. Count the number at 
least. 

To pass the test, S must name at least 60 words. Bright chil- 
dren can name from 100 to 200 : one child is recorded who named 
218. The performance of the child often throws Ught upon his 
intellectual equipment and general alertness. Clever children 
hit upon series of related terms, especially of abstract and descrip- 
tive terms. 

No. Jj-S. Definition of abstract terms.- 

Ask S: "What is charity"? "What is justice"? "What is 
kindness"? The test is passed if two of the three terms are defined 
acceptably. Most 11-year old children can pass the test, about 
one-third of 10-year old children, l)ut only a few can construct 
definitions at 8 or 9 years of age. 

The definition of charity should contain two ideas — that of unfortunates 
and that of the good that is done them : the definition of justice should 
contain either the notion of law or that of treating persons according to 
their merits: the definition of kindness should contain the notion of affec- 
tion, sentiment, tenderness, assistance, etc. 

No. 49. Arranging words in a sentence.^ 

This test differs from No. 43 in that all the parts of the sentence 
are supplied, and S has only to piece these together to ' make sense.' 
A time-limit oi 1 min. is placed upon each sentence : very bright 
*S's may effect the arrangement in 5 sec. 

Copy upon three small sheets of paper, with a typewriter or in 
legible script, the three mutilated sentences, following precisely 

'■ See Chapter IX, Test 33, for results of similar tests when applied to 
adults. 
'Cf. No. 30 of the 1st, and No. 5G of the present series. 
^Cf. Test 47, Chapter XI. 



TEST 54: BINBT-SIMON 1908 SERIES 511 

the arrangement here given. Hand S one sheet at a time and ask 
him to make a correct sentence (orally) from the words on the sheet 

(1) a (lofonds 
dog good his 
master courageously 

(2) my have teacher 
I the correct 
asked paper to 

(3) home our early 
we country in left 
visit the to friends 

The corrected Sentences are: (1) A good dog defends his master 
courageously. (2) I have asked the teacher to correct my paixn-. 
(3) We left .home early to visitrour^ friends in the country. 

J. TESTS FOR 12-YEAR OLD CHILDREN 

No. 50. Memory for seven digits. 

This is the same as No. 3. Let S know that there are to be 7 
digits. If he repeats all 7 correctly in 1 of 3 trials (3 different num- 
bers), the test is passed. 

No. 51. Rimes. 

Use No. 24 in the 1905 series to see if »S can make at least 3 
rimes in 1 min. 

No. 52. Memory for sentences {26 syllables). 

Children 12 years old should be ah)le to repeat the first 13 sen- 
tences oi No. 2. 

No. 53. Problems. 

This is another so-called 'common-sense' test. 
(1) Ask *S' to supply the missing word in the following: "A per- 
son who was walking in the woods in the park stopped in fright and 



512 



DEVELOPMENTAL DIAGNOSIS 



ran to the nearest policeman, saying that she had just seen hanging 
from the branch of a tree a ." 

(2) "My neighbor has been having queer visitors: first a doctor, 
then a lawyer, then a priest. What's happening there"? 

To pass the test, ))oth 'problems' must be solved. 

k. TESTS FOR 13-YEAR OLD CHILDREN. 

No. 54. Drawing from a design cut in a quarto-folded -paper. 

Follow the directions in No. 29 of the. 1905 series. If *S succeeds, 
ask him if he has tried the test before. 

No. 55. Juxtaposed triangles. 

Select a card of about twice the size of that represented in Fig. 
64. Cut it in two parts diagonally from a to b. Place the card Avith 
the two halves contiguous, in *S's view on a table, and say to him: 
"Look carefully at this card, especially at this [lower] half. Sup- 
pose we should turn this half upside down, and place this corner 
[c] touching this point [6] so that this edge [6c] shall touch this 
edge [6a], what would the whole figure look hke then? Now, I'm 
going to pick up this lower half. I want you to imagine it turned 
over and laid up against the upper half as I have said. Draw the 




FIG 64. THE TEST OF JUXTAPOSED TRIANGLES. 

(No. 55, 1908 Binot-Simon scries.) 



TEST 54: BINET-SIMON 1908 SERIES 513 

whole figure tor me, as it would look then. Begin Avith the upper 
half that you see before you." 

The test is difl&cult: the essential point for success is to preserve 
the right angle bca, and to make ch shorter than ha. 

No. 66. Distinctions hetwee?i abstract terms. 

This test is similar to No. 30 of the 1905 series, except in the 
choice of terms. Ask S: (1) "What is the difference between 
pleasure and happiness'"^. (2) "What is the difference between 
evolution and revolution''^ (3) "What is the difference between 
poverty and misery"? (4) "What is the difference between pride 
and pretention"? 

Treatment of Data. — In handling these numerous tests in 
serial arrangement for diagnostic purposes, the adoption of a 
simple system Of recording the data for the tests will be found 
helpful. The following suggestions are made to this end. Prepare 
a large record sheet on which the numbers and descriptive titles 
of the tests are spread out horizontally (somewhat as in Table 99). 
Divide the array of tests by vertical lines in accordance with the 
division by age-norms as already indicated. Enter the results for 
each child under the several tests, using convenient symbols, e.g., 
Y for complete success, S for partial success, P for poor outcome, 
for complete failure. It will then be possible and profitable 
to add a second symbol to indicate the nature or cause of the failure, 
e.g., A for a failure characterized by some absurdfty that indicates 
lack of judgment or common-sense, I for failure through ignorance, 
i.e., inability to comprehend what is wanted or to supply the answer, 
R for failure through resistance, stubbornness,, etc., T for failure 
through timidity, D for failure through defective attention (acci- 
dental distraction, preoccupation, scatter-brained condition, etc) . 
Partial success may also often be indicated by the use of a subjoined 
fraction (e.g., |) to indicate the proportion of the test performed 
correctly. 

When S's results have been distributed in this manner, E is 
next confronted with the problem of determining whether these 
results indicate normal, retarded, or advanced mental develop- 
ment. Since there can, in the nature of the case, be no hard and 



514 DKVELOPMKNTAL DIAGNOSIS 

fast lines, as there is no single, decisive test of intelligence, and 
since most S's who fail at a given test succeed with some of the 
tests of the next grade of difficulty (see Table 99), it follows that the 
determination of mental status must be based upon some quasi- 
artificial rule. Binet and Simon have found the following rules most 
serviceable in practise: (1) The intellectual status of a given S 
is that of the oldest age at which he can pass successfully all of 
the tests save one that are assigned to the age in question. But 
(2) to the intellectual level thus determined, E may add one year 
for every 5 tests that are passed above the year in question. A 
child whose final rank places him 3 years behind the norm of his 
age is to be considered mentally defective.^ 

In illustration: a boy 9 years old passed only 3 tests in that year: on the 
basis of Rule l,lus status is that of an 8-ycar child, or one year of retardation. 
But the same boy also passed 3 of the 10-year tests: hence he passed in all 
6 tests above the S-year limit, and therefore by Rule 2,*is entitled to rank 
"at age," or normal. In exceptional cases, this rule may necessarily be 
abrogated, or it may bo modified at E's discretion. 

Results. — (1) In the examination of 203 French children, 
aged 3-12 years, Binet and Simon found that 103 children ranked 
as of normal capacity: 42 were advanced 1 year; 2 were advanced 
2 years; 44 were retarded 1 year; 12 were retarded 2 years: in 
other words, about one-half were "at age," 44 were advanced, and 
56 were retarded.^ 

(2) Children selected by their teachers as possessing unusual 
ability invariably rank as 'advanced' in these tests: again, an 
examination of 14 children who were 3 years behind in school 
grades showed that all were retarded in these tests by from 1 to 
6 years (averaging 2.5 years). Both of these facts confirm the 
value of the series of tests. 

(3) Decroly and Degand have applied the 1908 series in Brussels 
to 45 normal children from well-to-do families. These writers 

'For illustrations of the application of the plan of rating the intelligence 
of a feeble-minded child in terms of the intelligence of a normal child at 
different ages, see Binet and Simon (2) . 

' The fact that only 14 of 203 children varied by as much as 2 years from 
the normal rating, demonstrates, in the opinion of the authors, that intel- 
lectual capacity, as measured by these tests, shows less variation than do 
such anthropometric values as height, weight, skull-capacity, etc. 



TEST 54: BINET-SIMON 1908 SERIES 515 

find the series valuable as a whole, but they regret the omission of 
certain of the 1905 tests which seemed to them of special value, 
and they do not find that Binet and Simon have been entirely 
successful, either in ehminating the effect of accidental school and 
home training, or in grading the tests correctly in respect to the 
several age-norms. Their critique is summarized in Table 100. 
It will be seen that there are, in substance;, six points of criticism. 
(a) Certain tests are too simple for the age to which the>' have been 
assigned. (6) Certain tests (in the 13th year) are too difficult for 
the assigned year, (c) Certain tests are too 'mechanical,' in that 
tho.y may be satisfied by a quasi-automatic form of response that 
does not compel the display of real intellectual ability.^ (d) 
Certain tests are too 'schooly' (trop scolaire), i.e., their outcome 
is to a greater 'or less degree contingent upon training that the 
child may have received either at home or at school, (e) The 
tests of rote memory should be graded to supply norms of perform- 
ance, now lacking, between the ages 7 and 12. (/) The sentence- 
building tests (Nos. 43 and 46) would be more valuable if they 
could be arranged* to permit verbal execution within a prescribed 
time-limit. 

TABLE 100 
Critiqiir of the 1908 Binel-Simon l^eriea. {Dccroly and Demand) 

NO. NAME CKITIC18M 

1 Comprehen.sion of language ("an be done earlier than 3d year 

.5 Family name Training 

6 Own sex Training 

7 Naming familiar objects Can be done earlier than 4th year 
13 Counting four pennies Training 

16 Elementary esthetic judgment Can be done at the 3d year 

17 Defining familiar objects Can be done at the 3d year 

18 Executing a tri-ple order Can be done at the 3d year 

19 Knowing own age Training 

22 Number of fingers Training 

23 Writing from copy Training 

25 Memory for digits Norms needed between 7th and 

12th year 

' Of these, Nos. 36 and 41 — reciting the days of the week and the months 
of the year — could, as Decroly and Degand suggest, be made non-mechanical 
by asking the child to recite the days or the months backward, or by asking 
him to name the day or the month preceding a given day or month. 



516 



DEVELOPMENTAL DIAGNOSIS 



NO. NAME 

27 Counting three pennies 

28 Naming four coins 

29 Reading and report 

30 Counting money 

31 Naming four colors 

32 Counting backwards 

33 Writing from dictation 

34 Differentiating from memory 

36 Reciting days of the week 

39 Reading and report 

40 Arranging five weights 

41 Reciting the months 
43 Sentence building 



Detecting absurdities 
Sentence building 
Naming words 



50 Memory for digits 

54 Drawing a cut paper 

55 Juxtaposed triangles 

56 Distinction abstract terms 



CRITICISM 

Too mechanical 

Training 

Training 

Training 

Can be done at the 4th year 

Training 

Training 

Can be done earlier than the 8th 
year 

Mechanical. Could be modified 

Training, at least for some children 

Can be done at 5th or 6th year "-• 

Mechanical. Could be modified %; 

Verbal execution should be per- 
mitted 

Can be done at the 6th year 

As 43 

Can be done earlier than the 11th 
year 

See No. 25 

Too difficult for 13th year 

Too difficult for 13th year 

Too difficult for 13th year 



Notes. — While these tests have been termed "a measuring 
scale of intehigence," it is not to be supposed that they have all 
the neatness and precision of the chemist's balance, or even of the 
calipers and tape of the anthropometrist. The criticisms of Decroly 
and Degand are sufficient evidence that we must do preliminary 
work in standardizing our tests before we can hope to rate the indi- 
vidual child with any accuracy. 

Furthermore, totally inexperienced E's can not expect to apply 
these tests with success. The elimination of delicate apparatus 
does not eliminate the need of skill and nicety in the administra- 
tion of tests, for the child's nervous system is more delicate than 
any instrument of precision. 

Particularly in applying these tests to the subnormal child, 
is the attitude of the examiner all-important. To quote from God- 
dard: "Always' the child must be won. Sometimes it is easy, 
sometimes it is difficult. The questioner should be very tactful 
and careful until he sees that the child is at ease ... At 



TEST 54: BINET-SIMON 1908 SERIES 517 

all events, get down to the level of the child. Never tell a child his 
answer is wrong. Always encourage. . . . On the other 
hand, do not insist that he respond, just because it seems to you 
that he must know. . . . While examining the child, forget 
all your preconceived ideas. Regard him as an unknown quan- 
tity, an X that is to be determined." 

REFERENCES 

(1) A. Binet and T. Simon, Le developpement de 1 'intelligence chez les 
enfants, in A. P., 14: 1908, 1-94. 

(2) A. Binet and T. Simon, L'intelligence des imbeciles, in A. P., 15: 
1909, 1-147. 

(3) O. Decroly and (Mile.) J. Degand, La mesure de 1' intelligence chez 
des enfants normaux d'apres les tests de Mm. Binet et Simon: nouvelle 
contribution critique, in Ar. P., 9: 1910, 81-108. 

(4) H. H. Goddard, A measuring scale for intelligence, in The Training 
School, 6: January, 1910, 146-155. 

(5) Dr. and Mrs. G. M. Whipple, The vocabulary of a three-year-old 
boy, with some interpretative comments, in Pd. S., 16: 1909, 1-22, espe- 
cially p. 19. 



LIST OF MATERIALS 



Roman numerals refer to test-numbers, italicized numerals to page- 
numbers. Items starred refer to materials that are recommended, but not 
prescribed, or to materials for the conduct of alternative or supplementary 
tests. 

rhe Materials may be ordered of C. H. Stoelting Company, 121 N. Green 
St., Chicago, Illinois, who will quote prices on application. 



I. SPECIAL APPLIANCES 



Adding machine, SI*. 
Acoumeter, Lehmann's, 18. 
Analyzer, Sommer's tridimensional, 

13*. 
Astigmatic chart, Verhoeff's, 14. 

Balls, five wooden, 52. 

Card of objects, Binet's, 32. 
Caliper, Vernier, 1. 
Calipers, head, 3. 
Color-blindness apparatus, Hering's 

Color-blindness cards, Nagel's, 16. 
Color-blindness worsteds, Holm- 
gren's, 16. 
Colored papers, set of four, 54. 
Conformateur, 3*. 
Counter, mechanical, 36*. 
Cubes, wooden, 52. 

Discrimination of brightness, Whip- 
ple's apparatus for, 17. 

Discrimination of grays, Whipple's 
apparatus for, 17. 

Dynamometer, back and leg, 7, 8. 

Dynamometer, Smedley's, 0, 9. 



Key, telegraph, 10*, 13. 
Krypteon, 25*. 

Kymograph, and accessories, 9, 
10, 13, 24*, 30*, 42. 

Lenses, trial, 14. 

Maddox rod, 15. 

Memory apparatus, Jastrow's, 38*. 

Mouth-pieces for spirometer, 5. 

Parallelopipeds, two wooden, 52. 

Pencil, electrical, 35*. 

Pendulum, second's, 10, 21, 22, 25*, 
38*. 

Picture, Australians, 32; Hindoos, 
31; The Disputed Case, 32; 
The Orphans' Prayer,32*; Wash- 
ington and Sally, 32*. 

Pictures, colored, set of eight, 53, 54. 

Pictures, colored, group of twelve 
on cardboard, 53. 

Pressure-pain balance, Whipple's, 
21, 22. 

Prism, twenty-degree, 36*. 

Prisms, set of four, 15. 

Pyramids, three wooden, 52. 



Ergograph, Mosso's, 9*. 
Esthesiometer, Jastrow's, 23. 

Fork, Blake's, 18. 

Fork, fifty-vibration, 24*. 

Forks for pitch discriminatio: 

Hammer, soft tipped, 19. 



Scales, anthropometric, 2. 
Signal-magnet, see time-marker. 
Smoking stand, see kymograph. 
Spirometer, 5. 
Stafliometer, 1. 

Steadiness tester, Whipple's, 13. 
Stenopaic lens, Stevens', 15*. 
Suggestion blocks, 40. 



519 



520 lilST <»!'' M ATMItlALS 

'r!il)l(>s 1)1' s(|iii.r(\s, cul.i's, vU-., nt". 'Vunv-uv.ukv.r, 10, 21*, 25*. 

'l'(i.l)l(!S, l^icllc's I'or iiuillii)licaM()ii. 'I'riiciiiu: hojird :uul stylus, 12. 

SI*. 

'r!U'liisl()sc()i)(>, \Vliii)])l(>'.s disc, 21, VViirinUi, illusory, eloetrical appara- 

2r). tus for, 44. 

'I'liinhour, Miucy. !•*, ."{()*. WarnUli, illusory, Guidi's appara- 

'l'ai)c, juit liroponu'ti'ic, 1. (us lor, 44. 

'rMi)pii)ji; ho.'ird ;iiid slyiiis, Whip- WcifJihts, fivo cul)ical, 53, M. 

!)l(>'s, 10. VV(>i!>;lils, For discrimination, 20. 

'r;ir>j;('( l)();ir<l, W liip|)lc's, 11. Wcif^lits, proj-iH^ssive, for suKK<'«- 

'rcsl-lypc, I 1. (ion, 11. 

II. SI'IK'IAL rniNI'l'M) I^'OIIMS 

Addilioii tc\s(, sec ('ouipu(u( ion. Mciiiorv, jilanks for r(>i)ro(lucrion, 

.Associ.'Uion; lOO-word test, WW; i)!ir(- ;iS." 

wliolt'S tost, ;{4; fiicMUs-spcM'ics MiMuorv for ideas: 'JMie Marble 

te.st, 'M; oi)i)osites (.es(s (llin-e S(a(ue, Cieero, and the Dutch 

ft)nns). ;M. iIonies(ead tests, 39. 

,, ,, . , Meinorv.di-ils for (forty-two cards) 

(Cancellation (ests; leKcrs ((wo ;>s; " ^ ^ •' ' 

forms) 2(;30*; Spanish (ex(,2(i; Mc.,Horv, let ter-squMres for Uen 

inissptMled words ((wo (onus), forius"), 3S. 

,, '■^''' . ,. ,,, ,. , MuKiplic.MlioM (es(s, see com])uta- 

(U)mple(ion (es( ol i'lhhiM^haus (j;,,, ' 

(three Conns). IS. 

(%)mpu(.'i(ion (es(s; addition Look. K,,.;,(lin- (est ((wo forms), 2S. 

.'if), iuldidoiiprohlems. Schul/.es 

inediod, .'55; addilion i)rol)lems, ^ , ^ i ,• .,. 

, 1,,, i:,.,;, , .>r. .ii:*:,., Sentences tor completion, 40 

t\\(-pl;ir.> dibits, .ii). a<idition ^;...„u.,.«..,.„o ...m;..„. oo 
prol>l(>ins, fwen(y-i)la('(> digit 



Simultaneous addinj;;, 29. 



.{f.; multiplication prol.lenvs .V,. -^tar, six-poin(ed 30. 

(\.un(inK .lo(s. twen(v-,sevei, l\>rins ''''^'''l'!^:'\^'^^\^'^(^'^t 
(ill .riinli.-.liO •>7 (I'orm A), 37; test strip (I'orm 

Desiijn.s for diiiwinn from memorw 

,V{. ■ T'lrtiet blanks. 11. 

Msth.Mie ju.liiineiK, lest {ov, .Yl. linllnishe.l piclures, 54. 

lM,nus,deSnn..tis' test-card of, A2. Vocabulary test , 50. 

Infonnat ion, ran.iie of, 51 , 

liik-i>lo(s, set of twenty. 15. Word-buildin,-'- (two formsX. 47. 

111. CllNMUAl. Arrid.WClsS .\\|) MAIMOKIALS 

Alcohol, <lenatured, II. ( '.-ndboard screen. 21, 22. 23, 30. 
AmiiuMer, 10*. t;j r,._> 



Uatterv, oi)en circuit. 10, 12 
22*, -IW 



Chair, typewriter, 10*, 13*. 

Chocolate, milk, 53. 

CiKarotlo, 31. 

Caixile, 15. CMamps, 9, 10. 24, 25. 

Cardboard, 10. 10. 24. 29, 37. 3S. 42. CMoth. gray, 10*, 17. 

43, 1 1. 40. 54. Cloth, soft black, 40. 41. 



LIST OF MA'I'KKIALt- 



52 1 



Coins (K) ]H!iuii(!S,5 nickels, 2 diiuos, 
'J (luarlcns, 1 Fiall'-dolliir, iuui 
I silver (lolhuO, 54. 

< 'ros«-s('ction paper, £0, 42. 

Cup, 63. 

Dividers, 11*. 
DoUiU- hill, 54. 

I)r:i\vinu; insi runienis, 24, 25, 42, 
4:{, 5;i, 51. 

(;i:iss, siicet, of, ;{()*. 
Ciinmicil icKcrs nud fi^nires, 24, 25, 
.'is. 

lie:ul-rcs(, 17, 24, 25. 

Key, onlin.'irj', 51}. 

Key, .sli<)rl,-cir(Mii(,in};-, 10, l.'J*. 

Lamp, ulcoliol, 44. 

jjiunp, clootric; IG-C. P. tubulai-, 

24, 25; 40-C. P. Uingsten 17; 

riil)y, 17;r(.urS-(l P., 44. 
Lrvcl, small, IS. 

Matches, 44, 53. 
Meter stick, 18. 
Metronome, 9, 11, 3S; with hell 

attaclunerit, 30*. 
Mirror, 30. 



Paper, 10X15 l)lanks,25; white, 15X 
50 cm., 42; heavy white, three 
she(>ts, 20 X 30 cm., 53; seven 
sheets, 15 X 20 cm., 53. 

Pencil, 2G, 2.S, 30; hard lead, 11. 

Penknife, 54. 

Pictures cut from maj'azines, 25. 

Pillow, 23. 

Resin, solution of, 10*. 
Rule, millimeter^ 1,0, 11. 

Scissors, 53, 51. 

iShellao solution, see kymofrraph. 

Snapi)er, telegraph, 18. 

Stamp, 2-cent postage, 31. 

Stoppers, ruboer, 18. 

Stop-watch, n, 10, 13, 18, 20-30, 

32-39, 44-48, 52. 
String, 53. 
Sui)ports, 9, 10, 17, 21, 22, 23, 24, 25, 

3(). 

'r;il)l(>, low, 13*, 21*, 40*. 
Telegraijli sounder, 12, 22*; with 

sjKMual pointer, 13. 
'rhumi) tacks, 30. 
TuIk', rubber, 18*, 30*. 

Wire, No. 18, insulated, 10, 12, 13, 

22*, 24*, 25*. 
Wood, piece of white, 53. 



INDEX OF NAMES 
Roman numerals refer to test-numbers, italicized numerals to page-numbers. 



Aars, K., 9 
Abney, W., 16 
Abt, G., 36 
Adsersen, H., 23 
Aiken, Catherine, 25, 401 
Aikins, H., 26, 34, 35 
Ament, W., 17 
Andrews, B. R., 18 
Aschaffenburg, 358 
Aubert, H., 17 
Ayers, E., 16 

Babbitt, E. H., 50 

Bagley, W. C, 37, 43, 45, 10, 11, 12, 
13 

Baird, . W., 16 

Barry, W. F., 14 

Baxt, N., 24 

Bayerthal,4, 

Becher, E., 24 

Bellei. 35 

Bentley, I. M., 38 

Bergstrom, J. A., 9, 38 

Bernstein, A., 38 

Bertillon, A., 47 J., 3 

Bettmann, S., 9 

Beyer, H. (1., 48, 5 

Bezold, F., 18 

Biedermann, 20 

Bigham, J., 35S 

Binet, A., 37, 45 H, 6,^7, 9, 10, 14, 22, 
23, 24, 26, 27, 29, 30, 31, 32, 33, 38, 
39, 41, 42, 43, 45, 46, 469, 53, 54. 

Bingham, W., 18 

Blazek, B.,23 

Bliss, C. B., 10 

Bryan, W. L.. 10, 11, 12 

Boas, F., 48, 1, 2, 3 



Bogdanoff, T., 310, 38 

Bolton, F. E., 40 

Bolton, T. L., 6, 9, 10, 12, 13, 21, 23, 

38 
Bonoff, N., 23 
Borst, Marie, 32 
Bouguer, P., 17 
Bourdon, B., 26, 38 
Bowditch, H. P., 48, 1 
Brackett, 13 
Bravais, 29 
Bridgman, Laura, 23 
Brown-Sequard, C. E., 23 
Browne, E., 14 
Bruner, F. G., 18 
Bryant, Sophie, 31, 33 
Bullard, 13 
Burgerstein, L., 35 
Burk, F., 48, 1, 2 
Burnett, C. T., 30 
Burnham, W. H., 38 
Burris, W. P., 35 
Burt, C, 24, 36, 38 

Calhoun, A. M., 14 
Calkins, Mary W., 33, 38 
Carman, Ada, 6, 22 
Carter, R. B., 14 
Cattell, J. McK., 9, 24, 26, 33 
Charpentier, A., 40 
Chrisman, O., IS 
Christopher, W. S., 2, 9 
Claparede, E., 32 
Claviere, J., 6, 9, 40 
Cohn, H., 14 
Cohn, J., 38 
Collin, 16 
Comstock, G. C, 26 



522 



INDEX OF NAMES 



523 



Courtier, J., 710 
Cramer, 310 
Crichton-Browne, J., 13 
Czermak, J. N., 23 

Dalton, J., 16 
Davis, 10. 

Davenport, C.B..9.27,46 
Davenport, E., 9, 12, 30,\39, 46 
Dawson, G. E., 4, 6, 22 
Dearborn, G., 45 
Dearborn, W. F., 3U, 350 
Decroly, O., 473, 53, 54 
Degand, J., 473, 53, 54 
Dehn,'w., 21, 22 
Delabarre, E. B., 13 
Delezenne, C. E. J., 19 
De Placzek, 32 
Dodge, R., 24 
Dove, H. W., 24 
Downey, June E., 36 
Dresslar, F. B., 10, 23, 40 
Diirr, E., 29, 46, 14 

Ebert, E., 38 

Ebbinghaus, H., 208, 35, 38, 441, 48 

Elderton, W. P., 9, 46 

Ellis, A. C, 9 

Ellis, H., 10, 22 

Elsenhans, T., 48 

Engelsperger, A., 48, 3 

Ephrussi, P., 38 

Erdmann, B., 24 

Ernst, Lucy, 4^ 

Exner, S., 24 

Farr, W., 48 
Farrand, L., 26 
Fechner, G., 18, 20 
Ferrari, 213 
Flournoy, Th., 33, 40 
Fox, W. S., 35 
Franklin, Mrs. C. L., 16 
Franz, S. I., 9 
Friedrich, J., 35 
Frobes. J., 17 



Gallon, F., 9, 29, 46 ff., 20, 38 

Gamble, Eleanor, 38 

Gartner, 216 

Geissler, L., 24, 30 ,356 

Gelle, A., 18 

Germann, G., 23 

Gihon, A., 48 

Gilbert, J. A., 1, 2, 5, 10, 17, 19, 20, 21, 

22, 40 
Gineff, D., 23 
Goddard, H. H., 52, 53, 54 
Goldscheider, A., 24 
Goltz, 216 
Gottschalk, 310 
Gould, G.M., 14 
Grashey, 238 
Gratsianoff, N. A., 49^1 
Greenwood, J. M., .^ 
Griesbach, H., 23 
Griffing, H., 21, 22, 24 
Guidi, G. 44 
Gulick, L. H., 47 
Gunther, 310 

Hall, G. S., 23, 4S8 

Hamilton, F., 24 

Hancock, J. A., 13 

Hansen, F., 18 

Harley, V., 9 

Hartwell, E., 49 

Hastings, W. W., 47, 49, 7,f8 

Hawkins, C. J., 38 

Hayes, S. P., 16 

Heller, T., 216 

Helmholtz, H., 17, 24 

Hempstead, Louise, 24 

Henderson, E. N., 39 

Henmon, V., 16 

Henri, V., 9, 23, 30, 31. 38, 39, 43, 45, 46 

Hertel, A., 47, 49 

Hitchcock, E., 47, 49 

Hitchcock, Jr., E., 49 

Hirschlaff, L., 9 

Hoch, A., 9 

Hodge, C. F., 9 



524 



INDEX OF NAMES 



Holmes, B., J^9 




Ley, 23 


Holmes, Marion E., 35 




Lindley, E. H., 9 


Holmgren, F., 16 




Lipmann, 0., 32, 48 


Hope, E., 14 




Lobsien, M., 32, 38 


Houdin, R., 25 




Lochte, 36 


Hough, T., 9^ 




Loeb, J., 9 


Hubbell, Elizabeth, 26, 


34, 35 


Loewit, 20 


Huey, E. B., 24 




Lombard, W. P., 9 


Hylan, J. P., 24, 25 




Lombroso, C, 18, 22 
Loomis, H. M., 40 


Jackson, Jr., W., ^9 




Luckey, G., 17 


Jacobs, J., 3S 




Luft, E., 19 


Jaffa, SIO 






Jastrovv, J., 13, 23, 30, 


33 


MacDonald, A., 49, 1, 2, 3, 4, 5, 6, 


Jennings, J. E., 16 




13, 22 


Johnson, G. E., 38 




Macmillan, D., 18 


Jones, E., 6, 35 




Malling-Hansen, P., 4^ 


Jost, A., 38 




Marsh, H. D., 9, 10, 35 


Joteyko, 84 




Martin, Lillie J., 20, 40 


Judfl, C, 23, 24, 26, 36 




Masson, V., 17 
Maurer, L., 32 


Kampfe, B., 130 




McDougall, W., 242, 30, 38 


Keller, K., 9, 35 




Merkel, J., 17, 21 


Kellor, Frances, 22, 23 




Merriman, M., 9, 15, 17, 27, 46 


Kelly, R. L., 10 




. Messmer, 0., 24 


Kemsies, F., 9, 35, 38 




Meumann, E., 48, 23, 24, 30, 35, ; 


Key, A., 47, W, 




469 


Kirkpatrick, E. A., 10, 


38, 45, 50 


Meyer, M., 23, 46, 19, 48 


Kline, L. W., 1, 2 




Michotte, 23 


Konig, A., 16 




Miller, Eleanora, 6, 9 


Kosog, 310 




Mobius, 4 


Kotelmann, L., 5, 14 




Monroe, W., 31 



38, 



Kraepelin, E., 9, 17, 23, 35, 313, 38, 48 
Krohn, W., 23 

Krueger, F., 29, 42, 44ff., 19, 35, 38, 48 
Kiilpe, O., 21 

Laprade, A., 36 

Larguier, J., 9, 38 

Laser, H., 35 

Le Clere, A., 31 

Lee, Alice, 3 

Lee, F. S., 9 

Lehmann, A., 30, 34, 46, 18 

Leuba, J., 23 



Moon, S., 49 

Moore, J. M., 10 

Mosso, A., 9 

Moure, 18 

Mliller, G.E.,9, 20, 38,40 

MuUer, R., 9, 24 

Mimsterbcrg, H., 239, 32, 358 

Nagel, W., 16 
Nelson, Mabel, L., 18 
Netolitzky, A., 35 
Netschajeff, A., 38 
Nevcrs, Cordelia, 33 



INDEX OF NAMES 



525 



Newsholme,'A., 14 

Nichols, L., 17 

Noikow,*'P., 23 

Norr, 18 

Norsworthy, Naomi, 34, 38 

Oehrn, A., 20, 35 
Offner, M., 23, 35, 38 
Okabe, T., 4U, 419, 4^8 
Oppenheim, SIO 
Ottolenghi, S., 22 
Oseretzkowsky, A., 9 

Paalhan, F., 30 
Pearson, K., 9, 29, 50 
Peckham, G., 50, 1 
Pedersen, R., 30, 34, 46 
Permewan, 18 
Philippe, J., 40 
Pieron, H., 17, 18 
Pilisbury, W. B., 24, 25 
Pilzecker, A., 38 
Pliischke, 306 
Pohlmann, A., 38 
Politzer, A., 18 
Porter,W. T.,50, 1,2, 3 
Preyer, W., 18, 19 

Quantz, J., 24, 25 

Raif, O., 10 
Reis, J., 35 
Reuther, F., 38 
Rice, J. F., 40 
Rietz, H., 14, 46 
Risley, S. D., 14 
Ritter, C, 23, 26, 38 
Rivers, W., 9 
Roberts, C, 50, 1 
Rodenwaldt, 310 
Rosmanit, J., 16 

Sack, 50, 1 
Sakaki, Y., 23 
de Sanctis, S., 52 

Sanford, E. C, 9, 15, 46, 18, 21, 24, 25 
26 



, 26, 28, 30, 31, 38, 39, 



Sargent, D. A., 47, 50, 7 
Schafhautl, C. E., 18 
Schirmer, O., 17 
Schmey, 23 
Schmidt-Rimpler, 14 
Schmiegelow, 18 
Schultz, G., 50 
Schulze, R., 23, 35 
Schumann, F., 38, 40 
Schuyten, M.-C, 6, 23, 38 
Scott, W.D.,4U, 44 
Scripture, E. W., 27, 46, 40, 44 
Seashore, C. E., 18, 19, 20, 40, 44 
Seaver, 47, 50, 7 
Seebeck, H., 19 
Seelye, H., 49 
Sergi, G., 50 
Sexton, 18 
Sharp, Stella E 

45, 46 
Shaw, J. C, 39 
Shermunski, 18 
Sherrington, C, 84 

Shipe, Maud, 9 

Simon, T., 23, 469, 53, 54 

Small, M. H., 44 

Smedley, F., 1, 2, 5, 6, 9, 10, 18, 

Smith, W. G., 10, 38 

Snell, S., 14 

Solomons, L., 13, 23 

Sommer, R., 13, 23 

Spearman, C, 9, 29/ , 33ff, 42, 44ff, 17, 
19, 20, 35, 38, 48 

Squire, Carrie R., 30 

Starch, D., 36 

Stein, Gertrude, 13 

Stern, L. W., 19, 32 

Stevens, G. T., 15 

Stilling, J., 14 

Storey, T., 9 

Stratton, G. M., 36 

Stratz, C, 50 

Stumpf, C, 19 

Sturgis, 13 

Swain. Y.,50 



38 



526 



INDEX OF NAMES 



Swift, E. J., 22, 49 
Suter, W. N., 15 

Tanner, Amy, 33 

Tarbell, G., 50 

Tawney, G., 23 

Teljatnik, 35 

Terman, L. W., 39, 47, 48, 49 

Thoma, R., 50 

Thompson, Helen, 10, 11, 12, 13, 17, 

19, 20, 21, 22, 23 
Thomson, W., 16 
Thorndike, E. L., 9, 12, 20, 26f., 46, 

9, 26, 34, 35 
Titchener, E. B.,9,46, 50, 10, 13, 128, 

130, 16, 17, 19, 20, 21, 23, 24, 30, 38 
Toulouse, E., 17, 18, 360 
Tucker, M. A., 13 

van Biervliet, J., 14, 17, 18, 20, 23, 

38, 40 
Vannod, Th., 22, 23 
Vaschide, N., 37, J^, 6, 7, 9. 10, 17, 

18, 22 
Vierordt, K., 5, 23 
Vogt, R., 26, 30, 35 
Volkmann, A.,17, 23, 24 
von Conta, 18 
von Frey, M., 208 
vonKries, J., 16 
vonReichard, 18 

Wagner, L., 23 
Washburn, Margaret, 23 
Weber, E. H., 20, 21, 23 
Weber, H., 36 



Wegener, H., 36 

Weil, 18 

Welch, G. T., 14 

Wells, F. L., 323, 10, 35 

Wendriner, 310 

Wernicke, C., 238 

Wertheimer, M., 48 

Wessely, R.,38 

West, G., 5i, 1, 2, 3 

Weygandt, W., 9 

Whipple, G. M., 10, 11, 37, 40, 46, 69, 
11, 19, 21, 22, 24, 25, 28, 32, 37, 
399, 414, 419, 437, 48, 50, 51, 54 

Whipple, Mrs. G. M., 50, 54 

Wiersma, E., 48 

Wigmore, J. H., 32 

Winch, W. H., 35, 38 

Winteler, J., 26, 27 

Wintrich, 5 

Wirth, F., 24, 364 

Wissler, C, 9, 46, 51, 1, U, 19, 20, 22, 
23, 26, 38, 39 

Withey, Donna L., 21 

Wolf, O., 18 

Wolfe, H. K., 40 

Wood, Anna, 47 - 

Wood, M., 51 

Wreschner, A., 32 

Wimdt, W., 130, 24 

Young, A. G., 14, 18 
Yule, v., 9, 32, 38/ . 

Zeitler, J., 24 
Ziegler, O., 48, 3 
Zollner, F., 24 



INDEX OF SUBJECTS 



For authors quoted, see Index of Names; for apparatus, see List of 
Materials. 



-4-test, see Cancellation 

Abnormal children, height of, 54; 
weight of, 59; diameter of skull 
of, 64; girth of skull of, 67; 
strength of grip of, 77; visual 
acuity of, 140; esthesiometric 
index of, 217; fidelity of report 
of, 307; efficiency of, in part- 
wholes test, 321; in genus-spe- 
cies test, 322; in opposites 
test, 325 f. ; in computation, 
341; in rote memory, 389 f. 
in Binet-Simon tests, 490 S. 
difficulty of examining, 489 
classification of, 492. See 
Graded tests and Truant schools 

Abstract terms, distinctions be- 
tween, 489, 513, 516; definitions 
of, 510; see Word tests 

Absurdities, detection of, 509, 516 

Accuracy, relation to speed, see 
Spec^d 

Addition, see Computation and Si- 
multaneous adding of, 7 f . ; 

Age, recording effect of, on height, 
54; on weight, 58; on diameter 
of skull, 63; on girth of skull, 67; 
on vital capacity, 71 .ff. ; on 
strength of grip, 75; on tapping, 
109; on aiming, 118; on tracing, 
122; on steadiness, 126; on vis- 
ual acuity, 139; on discrimi- 
nation of brightness, 164; on 
auditory acuity, 177 f., on pitch 
discrimination, 184 f . ; on dis- 
crimination of lifted weights. 



192; on sensitivity to pain, 203 f.; 
on esthesiometric index, 211 f.; 
on range of visual attention, 
236; on cancellation, 261; on 
speed on reading, 275; on fidel- 
ity of report, 306 f.; in part- 
wholes test, 321; in genus- 
species test, 322; in substitu- 
tion test, 353; on rote memory, 
376-379; on logical memory, 
399 f.; on size-weight illusion, 
407; in progressive weight test, 
413; in progressive line test, 
418; on contradictory sug- 
gestion, 421; on directive sug- 
gestion, 423; on illusory warmth, 
428; in ink-blot test, 433; in 
completion test, 451; on inter- 
pretation of fables, 457; on 
range of information, 466; know- 
ing own, test of, 500, 515 

Aiming test, 115-119 

Alcohol, effect of, on endurance, 97 

Amblyopia, 131 

Ametropia, 131, 134 1?. ; relation of, 
to heterophoria, 144 

Anregung, 95, 268 t.; in tapping, 
110; in computation, 334 

Anthropometric tests, 47-68 

Antrieb, see Spurts. 

Association, tests of, 312-343; un- 
controlled, 313-319, 510; con- 
trolled, 319-343 

Asthenopia, 131 

Astigmatism, 132 f., 137 f. 



527 



528 



INDEX TO SUBJECTS 



Attention, tests of, 221-285 
Auditory acuity, 166-180; relation 

of, to pitch discrimination, 185 
Aussage test, see Report, fidelity of 
Average deviation, comoutation of, 

15 f. 

Backward-alphabet test, 326 

Bertillon system, 60 ff. 

Binet-Simon graded tests, 1905 ser- 
ies, 473-492; 1908 series, 493-517 

Blind, esthesiometric index of, 216; 
size-weight illusion in, 409 

Brightness, discrimination of, 159- 
166 

Cancellation test, 254-270, 282 

Cephalic index, 62 ff. 

Change, test of making, 506 f. 

Chorea, 123 f . 

Class standing, see General intelli- 
gence 

Clock-hands, interchange of, 486 t. 

Color-blindness, 148-159 

Color-weakness, 151 f. 

Colors, naming four, 505, 516 

Comparison, tests of ability to 
make, with lines, 478, 496; with 
weights, 479, 497. 

Completion method (Ebbinghaus), 
445-454 

Computation tests, 327-343 

Contradictory suggestion, 419 ff. 

Copying a square, 497, a sentence, 
501, 515; a diamond, 503 

Correlation, of mental traits with 
general intelligence , 5 (see also 
General intelligence) ; measures 
of, 27^5; meaning of, 27 ff., 
45; computation of, 29-45; by 
product-moments method, 29- 
32; by method of rank-diffei- 
ences, 32 ff . ; by foot-rule method 
34 f.; by distribution, 35-38; 
by presence and absence, 38 f . ; 
by unlike signs, 40 f. 



Correlations, correction of attenu- 
ation in, 41 f.; correction of 
constriction or dilation in, 
43 f.; miscellaneous, with pitch 
discrimination, 185, 187; with 
lifted weights, 193; with sen- 
sitivity to pain, 206; with can- 
cellation, 267; with speed of 
reading, 276; with the opposites 
test, 326 f.; with computation, 
340; with rote memory, 390; 
with logical memory, 401; with 
progressive weight test, 414; 
with progressive line test, 419; 
with illusory warmth, 428; with 
development of sentences, 438; 
with development of themes, 
440; with word-building, 444 f. ; 
with the completion test, 453 

Counting, of dots, 270-273; on metro- 
nome beats, 282; of pennies, 
498, 503, 516; of money, 504 f., 
516; backwards, 505, 516 

Criminal type, in relation to sensi- 
tivity to pain, 205 f . ; to use of 
esthesiometfer, 208, 217 

Date, knowing the, 506 

Days of week, reciting, 506, 515 f. 

Deaf-mutes, 490 

Deafness, partial,prevalence of, 176 f. 

Defective children, see Abnormal 

children 
Defective eyesight, see Visual acii- 

ity 
Defective hearing, see Auaitory 

acuity 
Definition tests, 459 ff., 463 f., 465- 

468, 479 f., 489, 500, 507, 510 
De Sanctis' graded tests, 469-473 
Description, of an object, 286-292; 

of a picture, 495 f., 513 
Dextrality, defined, 74; in strength 

of grip, 77 
Diagnosis of development, tests for, 

see Graded tefsts 



INDEX OF SUBJECTS 



529 



Diagnosis-of-fact tests, 446, 454 

Dictation, 505, 516 

Differences, between objects, 480 
f., 516; between abstract terms, 
4S9, 516 

Digit tests, see Memory for digits 

Diplopia, 143 f. 

Directive suggestion, 421 ff. 

Discrimination, tests of, see Bright- 
ness, Esthesiometric index. 
Pitch, Lines, and Lifted weights 

Distraction, effect of, on computa- 
tion, 334; in memory tests, 366, 
369, 384 

Distribution, graphs of, 20 f . ; 
smoothing of, 21 f . : norma!, 
23-27 

Diurnal rhythm, in endurance, 96; 
in tapping, 112; in esthesiome- 
tric index, 212 f.; in computa- 
tion, 338 f. 

Divided rectangle test, 497 f. 

Division, see Computation 

Dominating letters, 239 f. 

Dot-tapping, McDougall's test of, 
282 f . 

Drawing from memory, 481 f . ; from 
cut design, 487 ff., 512, 516 

Dj'-namometer, objections to, 78 

Ebbinghaus test, see Completion 

method 
Esthetic judgment, 498 f., 515 
Electric counter, defects of, 106 f., 

126 
Endurance, of grip, 82-100; types of, 

92 f.; relation to vital capacity^ 

96 
Ennui, 334 f. 
Epileptics, rate of tapping of, 113 f. ; 

fidelity of report of, 307 
Error of mean square, see Standard 

deviation 
Ergograph, use of, see Grip, endur- 
ance of 
Esthesiometric index, 207-220 



Eye-muscles, balance and control 

of, see Heterophoria 
Eyesight, keeness of, see Visual 

acuity 

Family name test, 496, 515 
Fables, sec Interpretation of fables 
Fatigue, 5; measurement of, by 
strength of grip, 77; nature of, 
84 ff. ; measurement of, by the 
ergograph, 94 f . ; by tapping, 
107, 111 f.; by sensitivity to 
pain, 204 f.; by the esthesi- 
ometric index, 208, 213 ff.; by 
the cancellation test, 265; bj'- 
simultaneous activities, 284; 
by computation, 335-340; by 
rote memory, 385 f . ; by the com- 
pletion method, 451 f. 
Fatigue-index of studies, 95, 214 
Fingers, knowing number of, 501, 

515 
Food, tests of knowing and seeking, 

476 
Footrule formula applied to memory 
tests, 366 f. See Correlation 

General intelligence, i elation of, to 
height, 54 f.; to weight, 59; to 
diameter of skull, 64 f . ; to girth 
of skull, 67 f . ; to vital capacity, 
73; to strength of grip, 75 ff. ; 
to dext ality, 77; to endurance 
of grip, 96; to tapping, 113; to 
tracing, 122; to visual acuity, 
140; to discrimination of bright- 
ness. 164 f.; to auditory acuity, 
178; to pitch discrimination, 
186 f . ; to discrimination ot 
lifted weights, 193; to sensi- 
tivity to pain, 205; to esthesi- 
ometric index, 217; to range 
of visual attention, 237; to can- 
cellation, 265 ff. ; to dot-count- 
ing, 272 f.; to speed of reading, 
275; to simultaneous adding. 



530 



INDEX OF SUBJECTS 



27S; to simultaneous disparate 
activities, 279; to fidelity of 
report, 307; to mirror-drawing, 
348; to substitution, 353 f.; to 
rote memory, 379, 385-389; to 
logical memory, 401; to size- 
weight illusion, 408 f . to the com- 
plef ion test, 452 f. ; to interpre- 
t at ion of fables, 456 f . ; to size 
of vocabulary, 462 

Cieneral tendency, measures of, 
9-14 

Genus-species test, 321 f. 

Graded tests for ilevel()]Miiental 
diagnosis, 469-517 

Graphic method, 19-22 

Grays, discrimination of, see 
Brightness 

(hil), strength of, 74-79; cndui- 
ance of, 82-100 

Grouj) method compared with indi- 
vidual method, 5 f. 

Habit-fonuation, see Learning 

Handwriting, 373 

Hearing, keenness of, see Auditory 

acuity 
Height, measuicment of, 51-56; as a 

factor in vital capacity. 72 
Heterophoria, 142-149 
Heterotropia, 143 f. 
Holmgren test for color-blindness, 

151,153-156 
IIy])ero]Via, see ^"isual acuity 

Ideational type, elTect of, on visual 
apprehension, 253; on tidclity 
of report, 309 

Imagination, 429-457 

Imitation of gestures, 476 

Individual differences, in weight, 
,">S f. ; in diameter of skull, 63; 
in strength of grip, 75; in tap- 
ping, lOS; in tracing, 122; in 
pitch discrimination, 184 ff. ; in 
discrimination of lifted weights. 



191 f. ; in sensitivity to pain, 
204; in manner of reading, 240 
ff. ; in visual apprehension, 250 
f., 253; in speed of reading, 275; 
in executing simultmeous activ- 
ities, 284; in description of 
an object, 289-292; in computa- 
tion, 333; in the work curve, 
335; in mirror-drawing, 346; 
in substitution test, 353; in 
logical memory, 399; in progres- 
sive line test, 418; in directive 
suggestion, 422; in illusory 
warmth test, 428; in ink-blot 
test, 434 f.; in completing sen- 
tences, 439; in word-buiUling, 
442; in size of vocabulary. 461. 
See Variability 

Individual method compared with 
group method, 5 f. 

Incorrigible children, see Abnormal 
children and Truant schools 

Information test, see Range of in- 
formation and Knowing, tests 
of 

Ink-blots, 430-135 

Intellectual equipment, tests of. 
458-468 

Intelligence, see General intelli- 
gence 

Interpretation of fables, 454—157 
, Invention, see Imagination and 
Linguistic invention > 

Insane, rate of tapping in, 113 f . ; 
fidelity of report in, 307 

Instructions, need of clear and uni- 
form, 4 f., 200, 415, 420, 493 

Knowing, tests of, sec Age, Date. 
Days of week, Family name, 
Fingers, Months. INIorning and 
afternoon. Naming, Range of 
information. Sex 

Kyinographic records, general direc- 
tions for making. 102 f., 106 



INDEX OF SUBJECTS 



531 



Learning, tests of, 312, 343-355. See 
also Memory 

Letter-squares, method of, 368 f. 

Lifted weights, discrimination of, 
188-194 

Lines, comparison of, 478-496; dis- 
crimination of, 482. See Pro- 
gressive lines 

Linguistic invention, 435-441. See 
Sentence-building 

Logical memory, 394-403, 503 f. 

Lung capacity, see Vital capacity 

Maddox-rod test, 144-147 

Material-weight illusion, 409 f. 

Mean, computation of, 9-13; relia- 
bility of, 25 f. 

Mean variation, see Average devia- 
tion. 

Measures, treatment of, 9-46 

Median, computation of, 13 f. 

Memory, immediate, 278; tests of, 
312, 356-403; methods classified, 
356-361; for digits, 362-368, 
478 f., 482, 495 f., 503, 511, 515 
f . ; for sentences, 394, 480, 494 
f., 498, 511; for pictures, 481; 
for ideas, see Logical memory 

]\Iemory-span, see Rote memoiy 

Mental ability, see Abnormal chil- 
dren, General intelligence, and 
Graded tests 

Mental work, effect of, on ergogra- 
phic curves, 94 if. ; see Work 
curve 

Meumann's memory test, see Word 
tests 

Mirror-drawing, 343-350 

Mirror-writing, 349 

Missing weight, detection of, 483 

Missing words, 484; see Comple- 
tion method 

Misspelled-word test, see Cancella- 
tion 

Mode, computation of, 14 

Months, reciting the, 507, 515 f. 



Morning and afternoon, knowing, 
500 f . 

Motor capacity, tests of, 69-127 

Movement, see Motor capacity; 
accuracy of, see Aiming and 
Tracing; involuntary, see Stead- 
iness; precision of, see Aiming 
and Tracing; quickness of, see 
Tapping; rate of, see Tapping 

Multiplication, see Computation, 
tests of 

Musical ability, 185 £f., 440 f. 

Myopia, see Visual acuity 

Nagel test for color-blindness, 
156 ff. 

Naming objects, 477 f., 494, 496, 
515; coins, 503, 516; coins and 
bills, 508, 516; colors, 505, 516- 
words, 510, 516 

Normal curve, see Distribution, 
normal 

Norms, of height, 51 ff. ; of weight, 
58; of diameter of skull, 63 f.; 
of girth of skull, 67; of vital 
capacity, 71 f . ; of strength of 
grip, 75 f.; of strength of back, 
80 f.; of strength of legs, 82; 
for tapping, 109 f. ; for aiming, 
119; for discrimination of bright- 
ness, 164; for auditory acuity, 
174; for discrimination of pitch, 
18J; for lifted weights, 191; for 
discrimination of pressure, 197; 
for sensitivity to pain, 202 f.; 
for range of ^visual attention, 
231-235; for visual apprehension, 
250; for speed of reading, 275; 
for simultaneous reading and 
writing, 281; for Binet's card of 
objects, 300; for report tests at 
large, 304-308; for uncontrolled 
association, 315 f. ;in part-wholes 
test, 321; in genus-species test, 
322; in opposites test, 325 f . ; for 
mij'ror-drawing, 346; in substi- 



532 



INDEX OF SUBJECTS 



tution test, 353; in digit test of 
memory, 374; in letter-square 
test, 374 f . ; for memory of 
words, 380 f.; for logical mem- 
ory, 399; for size-weight illu- 
sion, 408; in progressive weight 
test, 412 f.; in progressive line 
test, 417 f.; for contradictory 
suggestion, 421; in, illusory 
warmth test, 427; in ink-blot 
test, 433; for developing sen- 
tences, 438; for word-building, 
442 f . ; for size of vocabulary,461 ; 
for range of information, 466; 
for Binet-Simon tests, 1905 
series, 489; for Binet-Simon 
tests, 1908 series, 514 ff. 

Opposites test, 323-326, 459 
Orders, tests of execution of, 476, 500, 
515 

Pain, sensitivity to, 198-207 

Part -wholes test, 320 f . 

Pauses, effect of, on work-curve, 338 

Perception, tests of, 221-285 

Perseveration, 372, 391 

Personal data, recording of, 7 

Physical capacity, tests of, 69-127 

Physical condition, effects of, on 
rote memory, 385 

Physical exercise, effect of, on ergo- 
graphic curves, 94, 97 

Picture tests, 477 f., 481, 495 f., 
501, 503; see Description, Report 
and Rote memory 

Pitch discrimination, 180-188; rela- 
tion of, to auditory acuity, 185 

Posture, effect of, on computation, 
334 

Practise, effect of, on endurance of 
grip, 93; on tapping, 112; on 
pitch discrimination, 185 f . ; 
on discrimination of lifted 
weights, 192 f.; on discrimina- 
tion of pressure, 197; on esthe- 



siometric index, 215; on range 
of visual attention, 235 f . ; on 
visual apprehension, 251 f . ; on 
cancellation, 264, 268 f . ; on 
fidelity of report, 309 f . ; on 
computation, 334; on mirror- 
, drawing, 346 f . ; on rote memory, 
384 f.; on logical memory, 401; ^ 
on size-weight illusion, 408; in 
progressive weight test, 413, in 
completion test, 451 ; see Trans- 
fer of practise. 

Precocity, see General intelligence 

Prehension, 475 f. 

Presbyopia, 131 

Pressure, discrimination of, 194, 
198 

Prism test, for heterophoria, 147 
f.; of associative connections, 
348 

Probability curve, see Distribution, 
normal 

Probable error, computation of, 
17 f.; relation of, to normal 
curve, 23 f . ; of mean and of 
other measures, 24-27; of coef- 
ficient of correlation, 31 

Problem-questions, 485 f., 508, 511 f. 

Progressive lines, test of, 414-419 

Progressive weights, test of, 410-414 

•Quality of work, relation of, to 
quantity of work, 6 f.. 333, 
341, 438; see Speed, relation of, 
to accuracy 

Questions, types of, 294 f . ; see Prob- 
lem-questions 

Racial differences in auditory acu- 
ity, 178 

Range of attention, see Simultane- 
ous adding. Simultaneous dis- 
parate activities. Visual appre- 
hension, and Visual attention 

Range of information, 465-408; see 
Knowing 



INDEX OF SUBJECTS 



533 



Reading, analysis of processes in, 
237-242; tests of, 273-277, 503 f., 
507; complicated prose, 273-277 

Regressive inhibition, 372 

Report, fidelity of, 2S6, 292-311, 
504 f., 507 

Resemblances among objects, test 
of, 482 

Right and left, knowing, 498 

Righthandedness, index of, 77; in 
tapping, 107, 110; in aiming, 
119; in tracing, 122; relation of, 
to visual acuity, 140 

Rimes, 483 f., 511 

Rote memory, 356-393; see Memory 
for digits. Memory for sen- 
tences, Word tests of memory 

Rules, general, for conduct of tests, 
4-8 

Sensory capacity, general method 
of measuring, 128 ff. ; tests of, 
128-220 

Sentence-building, 484 f, 508 ff., 
515 f.; See Linguistic inven- 
tion 

Sentences, development of, 436 ff. ; 
completion of, 438 f.; see M'- ^- 
ory for sentences 

Sex, knowing oy^n, ^96, 515 

Sex-differeflces, in height, 53 f.; 
IB 'weight, 58; in diameter of 

^ 'skull, 63; in girth of skull, 67; 
in vital capacity, 72; in strength 
of grip, 75; in endurance of 
grip, 96; in tapping, 109 ff. ; in 
aiming, 119; in tracing, 12'2; in 
steadiness, 164; in auditory 
acuity, 178; in ^itch discrimina- . 
tion, 184; in discrimination of 
lifted weights, 192; in discrimi- 
nation of pressure, 197; in sen- 
sitivity to pain, 203; in esthesi- 
ometric index, 211; in range of 
visual attention, 237; in can- 



cellation, 261; in description, 
289; in fidelity of report, 305 
f . ; in uncontrolled association, 
316 ff. ; in opposites test, 325; 
in computation, 333; in mirror- 
drawing, 346; in substitution 
test, 353; in rote memory, 375; 
in logical memory, 399; in size- 
weiglit illusion, 407 f . ; in illu- 
sory -warmth, 428; in word- 
building, 444 f . ; in the comple- 
tion test, 451; in size of vocabu- 
lary, 461 f . ; in range of informa- 
tion, 466 
Simultaneous adding, 277 ff. 
Simultaneous disparate activities, 

279-285, 366, 369 
Size-weight illusion, 405-410 
Skull, diameter of, 60-66; girth ot, 

66 ff. 
Sociological status, relation of, to 
height, 54; to weight. 59; to 
girth of skull, 67; to strength 
of grip, 76; to tapping, 113; to 
visual acuity, 139; to sensitivity 
to pain, 205 
Space threshold, seoisthesiometric 

index 
£,peed, relation of, to accuracy, 6 f.; 
in cancellation, 260 f., 263 f.; 
in dot-counting, 273; in mirror- 
drawing, 347 f. ; see Quality of 
work 
Spelling, 373, 390, 444 
Spot-pattern test, 242 f. 
Spurts, 110 f., 334; see Work curve 
Square test, see Copjdng a square 
Standard deviation, computation 
of, 16 f . ; relation of, to normal 
curve, 23 f. . 

Ste_adiness test, 123-127 ^"^ 
Strabismus, see Heterophoria 
Strength, of grip, 74-79; of back, 

79-82; of legs, 82 
Substitution test, 350-355 
Subtraction, see Computation 



534 



INDEX OF SUBJECTS 



Suggestibility, tests of. 299 ft., 
308, 404^28, 477 ff. 

Suggestion, effect of, on esthesio- 

^ metric index, 216; of line 
lengths, 419-423; see also Pro- 
gressive lines and Suggestibility 

Suggestion-blocks, see Size-weight 
illusion 

Tachistoscope, technique of, 222- 

226, 245 ff. 

Tapping test, 100-115 

Tastes, literary and artistic, 435 f., 
459 

Testimony, psychology of, see Re- 
port, fidelity of 

Tests, mental, general nature and 
purpose of, 1 ff. 

Theme, development of, 440 f.: 
choice of, 441 

Time-limit method, 6 

Tobacco, effect of, on omluranco. 97 

Tracing test, 119-123 

Training, see Practise 

''^r of practise, in mirror- 
in memory 



Unfinished pictures, test of, 501 f. 
Unidexterity, see Righthandedness 

Variability, measures of, 15-19, 26 f . ; 
coefficient of, 19; m ergographic 
curves, 95 

Visual acuity, 131-142 

VJ3ual apprehension, 244-254 
isual attention, 222-244 

Visual coordination, 475 

Vital capacity, 70-74; as related to 
endurance, 96 

Vital index, 72 

Vocabulary, a factor in word-build- 
ing, 444; size of, test for, 458- 
464 



Warming-up, 110 
Warmth, illusory, 423-428 
Weight, measurement of, 56-60 
Weights, arrangement of five, 483, 
507, 516; see Comparison of 
weights. Lifted weights, Miss- 
ing weight 
Word-building, 441^45 
Word-tests of rote memory, 369-374 
Words, arrangement of, see Sen- 
tence-building 
tests^Ca-v curve, analysis of, 334-340 
in weight, w-;.:, method, 6 

«trength of g:^n!';sSsio^ '^^^^"^' ^^^''' '' ''''' '^^" 

metric index of, 217; interpreta- 
tion of fables bv. 457 



tests,'^^^^!- 



^"angles, test of ju.vtap.. ,^6 
Truant and reform school 

boys in, in height, 54 

59; in vital 



dictation, 505"^<^ Copying 









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